Which of the following is a displacement reaction?
2. Magnesium ribbon is rubbed before burning because it has a coating of
(a) basic magnesium carbonate
(b) basic magnesium oxide
(c) basic magnesium sulphide
(d) basic magnesium chloride
3. Which of the following statements about the given reaction are correct?
3Fe (s) + 4H2O (g) → Fe3O4 (s) + 4 H2 (g)
(i) Iron metal is getting oxidised
(ii) Water is getting reduced
(iii) Water is acting as reducing agent
(iv) Water is acting as oxidising agent
(a) (i), (zi) and (iii)
(b) (in) and (iv)
(c) (i), (ii) and (iv)
(d) (ii) and (iv)
4. Which of the following are exothermic processes?
(i) Reaction of water with quick lime
(ii) Dilution of an acid
(iii) Evaporation of water
(iv) Sublimation of camphor (crystals)
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (i) and (iv)
(d) (ii) and (iv)
5. Oxidation is a process which involves
(a) addition of oxygen
(b) addition of hydrogen
(c) removal of oxygen
(d) removal of hydrogen
6. The process of reduction involves
(a) addition of oxygen
(b) addition of hydrogen
(c) removal of oxygen
(d) removal of hydrogen
7. Three beakers labelled as A, B and C each containing 25 ml of water were taken. A small amount of NaOH, anhydrous CuSO4 and NaCl were added to the beakers A, B and C respectively. It was observed that there was an increase in the temperature of the solution contained in beakers A and B, whereas in case of beaker C, the temperature of the solution falls. Which one of the following statement(s) is (are) correct?
(i) In beakers A and B, exothermic process has occurred.
(ii) In beakers A and B, endothermic process has occuBftd.
(iii) In beaker C exothermic process has occurred.
(iv) In beaker C endothermic process has occurred.
(a) (i) only
(b) (ii) only
(c) (i) and (iv)
(d) (iv), (ii) and (iii)
8. Give the ratio in which hydrogen and oxygen are present in water by volume.
(a) 1:2
(b) 1:1
(c) 2:1
(d) 1:8
9. Which among the following statement(s) is (are) true?
Exposure of silver chloride to sunlight for a long duration turns grey due to
(i) the formation of silver by decomposition of silver chloride
(ii) sublimation of silver chloride
(iii decomposition of chlorine gas from silver chloride
(iv) oxidation of silver chloride
(a) (i) only
(b) (i) and (iii)
(c) (ii) and (iii)
(d) (iv) only
10. MnO2 + 4HCl → 2 + 2H2O + Cl2
Identify the substance oxidized in the above . equation.
(a) MnCl2
(b) HCl
(c) H2O
(d) MnO2
11. A substance ‘X’ is used in white-washing and is obtained by heating limestone in the absence of air. Identify ‘X’.
(a) CaOCl2
(b) Ca (OH)2
(c) CaO
(d) CaCO3
12. When Ag is exposed to air it gets a black coating of
(a) AgNO3
(b) Ag2S
(c) Ag2O
(d) Ag2CO3
13. Which of the following is an endothermic process?
(a) Dilution of sulphuric acid
(b) Sublimation of dry ice
(c) Condensation of water vapours
(d) Respiration in human beings
14. In the double displacement reaction between aqueous potassium iodide and aqueous lead nitrate, a yellow precipitate of lead iodide is formed. While performing the activity if lead nitrate is not available, which of the following can be used in place of lead nitrate?
(a) Lead sulphate (insoluble)
(&) Lead acetate
(c) Ammonium nitrate
(d) Potassium sulphate
15. What type of chemical reactions take place when electricity is passed through water?
(a) Displacement
(b) Combination
(c) Decomposition
(d) Double displacement
16. Select the oxidising agent for the following reaction:
H2S + I2 > 2HI + S
(a) I2
(b) H2S
(C) HI
(d) S
17. A substance added to food containing fats and oils is called:
(a) Oxidant
(b) Rancid
(c) Coolant
(d) Antioxidant
18. The condition produced by aerial oxidation of fats and oils in foods marked by unpleasant smell and taste is called:
(a) antioxidation
(b) reduction
(c) rancidity
(d) corrosion
19. Electrolysis of water is a decomposition reaction. The mole ratio of hydrogen and oxygen gases liberated during electrolysis of water is:
(a) 1 : 1
(b) 2:1
(c) 4:1
(d) 1:2
20. When S02 gas is passed through saturated solution of H2S, which of the following reaction occurs?
(a) SO2 + 2H2S → 2H20 + 3S
(b) SO2 + 2H2S → H20 + 3S
(c)SO2 + H2S → H2O + S
(d) SO2 + H2O → SO3 + H2
21. Name the products formed when iron filings are heated with dilute hydrochloric acid
(a) Fe (III) chloride and water
(b) Fe (II) chloride and water
(c) Fe (II) chloride and hydrogen gas
(d) Fe (III) chloride and hydrogen gas
22. Pb + CuCl2 → PbCl2 + Cu
The above reaction is an example of:
(a) combination
(b) double displacement
(c) decomposition
(d) displacement
23. Which of the following gases can be used for storage (a) Carbon dioxide or Oxygen
(b) Nitrogen or Oxygen
(c) Carbon dioxide or Helium
(d) Helium or Nitrogen
24. A dilute ferrous sulphate solution was gradu¬ally added to the beaker containing acidified permanganate solution. The light purple colour of the solution fades and finally disap¬pears. Which of the following is the correct explanation for the observation?
(a) KMnO4 is an oxidising agent, it oxidises FeSO4.
(b) FeSO4 acts as an oxidising agent and oxidises KMNO4.
(c) The colour disappears due to dilution; no reaction is involved.
(d) KMnO4 is an unstable compound and de-composes in presence of FeSO4. to a colourless compound.
25. In which of the following chemical equations, the abbreviations represent the correct states of the reactants and products involved at reaction temperature?
(a) 2H2 (l) + O2 (l) > 2H2O(g)
(b) 2H2 (g) + O2 (l) > 2H2O (l)
(c) 2H2 (g) + O2 (g) > 2H2O (l)
(d) 2H2 (g) +O2 (g) > 2H2O (g)
26. The addition of oxygen to a substance is called …………. whereas removal of oxygen is called …………. .
27. The addition of hydrogen to a substance is called …………. whereas removal of hydrogen is called …………. .
28. Precipitation reactions produce insoluble …………. .
29. Reactions in which energy is given out are known as …………. .
30. Reaction in which an element displaces another element from its compound is called …………. .
31.Two antioxidants which are usually added to fat and oil containing foods to prevent rancidity, are …………., …………. .
32. …………. is the process in which metals are eaten up gradually by the action of air, moisture or a chemical on
their surface.
33. 2 FeSO4 → Fe2O3 + SO2 + ………….
33. Na2SO4 + BaCl2 → …………. + 2NaCl
34. Complete the missing components/variables given as x and y in the following reactions:
(a) Pb (NO3)2 (aq) + 2KI (aq) → Pbl2 (x) + 2KNO3 (y)
(b) Cu (s) + 2AgNO3 (aq) → Cu (NO3)2 (aq) + x (s)
35. Before burning in air, the magnesium ribbon is cleaned by rubbing with a sand paper to:
a. Make the ribbon surface shinier
b. Remove the layer of magnesium oxide from the ribbon surface
c. Remove the layer of magnesium carbonate from the ribbon surface
d. Remove the moisture from the ribbon surface
36. In a chemical reaction between sulphuric acid and barium chloride solution the white precipitates formed are of:
a. Hydrochloric acid
b. Barium sulphate
c. Chlorine
. All the methods mentioned below can be used to prevent the food from getting rancid except:
i. Storing the food in the air-tight containers
ii. Storing the food in refrigerator
iii. Keeping the food in clean and covered containers
iv. Always touching the food with clean hands
a. (i) and (ii)
b. (i) and (iii)
c. (i), (iii) and (iv)
d. (iii) and (iv)
37. Rusting of iron involves a chemical reaction which is a combination of:
a. Reduction as well as combination reactions
b. Oxidation as well as combination reactions
c. Reduction as well as displacement reactions
d. Oxidation as well as displacement reactions
38. The respiration process during which glucose undergoes slow combustion by combining with oxygen in the cells of our body to produce energy, is a kind of:
a. Exothermic process
b. Endothermic process
c. Reversible process
d. Physical process
39. A chemical reaction does not involve:
a. Formation of new substances having entirely different properties than that of the reactants
b. Breaking of old chemical bonds and formation of new chemical bonds
c. Rearrangement of the atoms of reactants to form new products
d. Changing of the atoms of on element into those of another element to form new products
40. One of the following processes does not involve a chemical reaction. That is:
a. Melting of candle wax when heated
b. Burning of candle wax when heated
c. Digestion of food in our stomach
d. Ripening
41. It is necessary to balance a chemical equation in order to satisfy the law of:
a. Conservation of motion
b. Conservation of momentum
c. Conservation of energy
d. Conservation of mass
42. All the methods mentioned below can be used to prevent the food from getting rancid except:
i. Storing the food in the air-tight containers
ii. Storing the food in refrigerator
iii. Keeping the food in clean and covered containers
iv. Always touching the food with clean hands
a. (i) and (ii)
b. (i) and (iii)
c. (i), (iii) and (iv)
d. (iii) and (iv)
43. Rusting of iron involves a chemical reaction which is a combination of:
a. Reduction as well as combination reactions
b. Oxidation as well as combination reactions
c. Reduction as well as displacement reactions
d. Oxidation as well as displacement reactions
44. You are given the following chemical reaction:
This reaction represents:
a. Combination reaction as well as double displacement reaction
b. Redox reaction as well as displacement reaction
c. Double displacement reaction as well as redox reaction
d. Decomposition reaction as well as displacement reaction
45. When ferrous sulphate is heated strongly it undergoes decomposition to form ferric oxide as a main product accompanied by a change in colour from:
a. Blue to green.
b. Green to blue.
c. Green to brown.
d. Green to yellow
46¹. Which of the following gases is used in the storage of fat and oil containing foods for a long time?
a. Carbondioxide gas
b. Nitrogen gas
c. Oxygen gas
d. Neon gas
47. Following is given a diagram showing an experimental set-up:
The given set-up is used to carry out:
a. Distillation of water
b. Purification of water
c. Electrolysis of water
d. Hydrolysis
48. The displacement reaction between iron (III) oxide and a metal X is used for welding the rail tracks. Here X is:
a. Copper granules
b. Magnesium ribbon
c. Sodium pellets
d. Aluminium dust
49. The neutralization reaction between an acid and a base is a type of:
a. Double displacement reaction
b. Displacement reaction
c. Addition reaction
d. Decomposition reaction
50. The chemical reaction between Hydrogen sulphide and iodine to give Hydrogen iodide and sulphur is given below:
The reducing and oxidizing agents involved in this redox reaction are:
a. Iodine and sulphur respectively
b. Iodine and hydrogen sulphide respectively
c. Sulphur and iodine respectively
d. Hydrogen sulphide and sulphur
51. Reaction of ‘magnesium’ with air is
A) Exothermic reaction
B) Endothermic reaction
C) Reversible reaction
D) Substitution reaction
52. What chemicals are used in fireworks?
A) Copper chloride
B) Calcium chloride
C) Barium chloride
D) All of above
53- When a magnesium ribbon is burnt in air, the ash formed is
A) Black
B) White
C) Yellow
D) Pink
54- Color of magnesium oxide is
A) White
B) Blue
C) Grey
D) Pink
55. If magnesium is gently heated, it forms
A) Magnesium oxide
B) Magnesium sulfide
C) Magnesium nitrite
D) Magnesium carbonate
56- When carbon dioxide is passed through lime water,
A) Calcium hydroxide is formed
B) White precipitate of CaO is formed
C) Lime water turns milky
D) Color of lime water disappears.
57- When crystals of lead nitrate are heated strongly in a dry test tube
A) Crystals immediately melt
B) A brown residue is left
C) White fumes appear in the tube
D) A yellow residue is left
58- Color of Solid magnesium is
A) Dark grey
B) Silver grey
C) Black
D) Whitish silver
59- Consider equations: Ca⁺²(aq) + 2OH‾(aq)→Ca(OH)₂ (s). Precipitate of calcium hydroxide will be of
A) Green color
B) Blue color
C) Brown color
D) White color
60- In writing chemical equations, inclusion of state symbols shall be done while
A) Correct chemical formulae of reactants and products are written
B) The equation is being balanced to fulfill the law of conservation of mass
C) The equation has been balanced
D) The chemical formulae of products and reactants have been changed to bring about quick balancing
61- Consider equation: Pb⁺² (aq) + 2OH⁻ (aq) → Pb(OH)₂ (s). precipitate of lead (II) hydroxide will be of
A) Green color
B) Blue color
C) Brown color
D) White color
62- Consider equation: Cu⁺² (aq) + 2OH⁻(aq) → Cu(OH)₂ (s). precipitate of Copper Hydroxide (Cu(OH)₂) will be of
A) Green color
B) Blue color
C) Brown color
D) White color
63- Consider reaction: Na(s) + O₂(g) → Na₂O(s). Moles of sodium needed to balance equation would be
A) 1
B) 2
C) 3
D) 4
64- Consider reaction: S(s) + O₂(g) → SO₂. state of SO₂ in this reaction is
A) Liquid
B) Solid
C) Gaseous
D) All Three
65- Consider reaction: P(s) + O₂(g) → P₄O₁₀(s). Moles of O₂(g) needed to balance equation will be
A) 1
B) 3
C) 5
D) 7
66- Consider reaction: Na(s) + O₂(g) → Na₂O. Moles of oxygen needed to balance equation are
A) 1
B) 2
C) 3
D) 4
67- Consider reaction: Al(s) + O₂ (g) → Al₂O₃. Moles of Al(s) needed to balance equation are
A) 1
B) 2
C) 3
D) 4
68- Which one of the given processes involves chemical reactions?
A) Storing of oxygen gas under pressure in a gas cylinder
B) Keeping petrol in a China dish in the open
C) Liquefaction of air
D) Heating copper wire in the presence of air at high temperature
69- In which of the given chemical equations, the abbreviations represent the correct states of the reactants and products involved at reaction temperature?
A) 2H₂ (l) + O₂ (l) → 2H₂O (g)
B) 2H₂ (g) + O₂ (l) → 2H₂O (g)
C) 2H₂ (g) + O₂ (g) → 2H₂O (l)
D) 2H₂ (g) + O₂ (g) → 2H₂O (g)
70- The reaction in which two compounds exchange their ions to form two new compounds is called
A) Displacement reaction
B) Combination reaction
C) Double displacement reaction
D) Redox reaction
71- On immersing an iron nail in CuSO₄ solution for a few minutes, you will observe
A) No reaction takes place
B) The color of solution fades away
C) The surface of iron nails acquire a black coating
D) The color of solution changes to green
72- Which of the given statements is not a physical change?
A) Boiling of water to give water vapour
B) Melting of ice to give water
C) Dissolution of salt in water
D) Combustion of Liquefied Petroleum Gas (LPG)
73- An element X on exposure to moist air turns reddish-brown and a new compound Y is formed. The substances X and Y are
A) X = Fe, Y = Fe₂O₃
B) X = Ag, Y = Ag₂S
C) X = Cu, Y = CuO
D) X = Al, Y = Al₂O₃
74- The reaction of H₂ gas with oxygen gas to form water is an example of
A) Combination reaction
B) Redox reaction
C) Exothermic reaction
D) All of these reactions.
75- Rancidity can be prevented by
A) Adding antioxidants
B) Storing food away from light
C) Keeping food in refrigerator
D) All of these
76- In which of the given, heat energy will be evolved?
A) Electrolysis of water
B) Dissolution of NH₄Cl in water
C) Burning of L.P.G.
D) Decomposition of AgBr in the presence of sunlight
77- Dilute hydrochloric acid is added to granulated zinc taken in a test tube. The following observations are recorded. Point out the correct observation.
A) The surface of metal becomes shining
B) The reaction mixture turns milky
C) Odour of a pungent smelling gas is recorded
D) A colorless and odourless gas is evolved
78- Consider reaction is an example of
(a) 4NH₃ (g) + 5O₂ (g) → 4NO (g) + 6H₂O (g) (a). Displacement reaction,
(b) Combination reaction
(c) Redox reaction
(d) Neutralization reaction.
A) (A) & (D)
B) (B) & (C)
C) (A) & (C)
D) (C) & (D)
79- Which of the following statements about the given reaction are correct? 3Fe(s) + 4H₂O(g) → Fe₃O₄ (s) + 4H₂ (g)
(a) Iron metal is getting oxidized.
(b) Water is getting reduced.
(c) Water is acting as reducing agent.
(d)Water is acting as oxidizing agent.
A) (A), (B) & (C)8
B) (C) & (D)
C) (A), (B) & (D)
D) (B) & (D)
80- Which of the following are exothermic processes?
(a) Reaction of water with quick lime
(b) Dilution of an acid
(c) Evaporation of water
(d) Sublimation of camphor (crystals)
A) (A) & (B)
B) (B) & (C)
C) (A) & (D)
D) (C) & (D)
81- A dilute ferrous sulphate solution was gradually added to the beaker containing acidified permanganate solution. The light purple color of the solution fades and finally disappears. Which of the given equation is the correct explanation for the observation?
A) KMnO₄ is an oxidizing agent, it oxidizes FeSO₄
B) FeSO₄ acts as an oxidizing agent and oxidizes KMnO₄
C) The color disappears due to dilution, no reaction is involved
D) KMnO₄ is an unstable compound and decomposes in the presence of FeSO₄ to a colourless compound
82- Which among the following statement(s) is /are true? Exposure of silver chloride to sunlight for a long duration turns grey due to-
(a) The formation of silver by decomposition of silver chloride.
(b) Sublimation of silver chloride.
(c) Decomposition of chlorine gas from silver chloride.
(d) Oxidation of silver chloride.
A) Only (A)
B) (A) & (C)
C) (B) & (C)
D) Only (D)
83- Solid calcium Oxide reacts vigorously with water to form calcium hydroxide accompanied by liberation of heat. This process is called slaking of lime. Calcium hydroxide dissolves in water to form its solution called lime water. Which among the following is are true about slaking of lime and the solution formed?
(a) It is an endothermic reaction.
(b) It is exothermic reaction.
(c) The pH of the resulting solution will be more than seven.
(d) The pH of the resulting solution will be less than seven.
A) (A) & (B)
B) (B) & (C)
C) (A) & (D)
D) (C) & (D)
84- Barium chloride on reacting with ammonium sulphate forms barium sulphate and ammonium chloride. Which of the following correctly represents the type of the reaction involved?
(a) Displacement reaction
(b) Precipitation reaction
(c) Combination reaction
(d) Double displacement reaction
A) Only (A)
B) Only (B)
C) Only (D)
D) (B) & (D)
85- Which of the following is (are) an endothermic process(es)?
(a) Dilution of sulphuric acid
(b) Sublimation of dry ice
(c) Condensation of water vapours
(d) Evaporation of water
A) Both (A) & (C)
B) Only (B)
C) Only (C)
D) Both (B) & (D)
86- In the double displacement reaction between aqueous potassium iodide and aqueous lead nitrate, a yellow precipitate of lead iodide is formed. While performing the activity if lead nitrate is not available, which of the given can be used in place of lead nitrate?
A) Lead sulphate (insoluble)
B) Lead acetate
C) Ammonium nitrate
D) Potassium sulphate
87- Which of the given gases can be used for storage of fresh sample of an oil for a long time?
A) Carbon dioxide or oxygen
B) Nitrogen or oxygen
C) Carbon dioxide or helium
D) Helium or nitrogen
88- Fatty foods become rancid due to the process of ________
A) Oxidation
B) Corrosion
C) Reduction
D) Hydrogenation
89- Which information is not conveyed by a balanced chemical equation?
A) Physical states of reactants and products
B) Symbols and formulae of all the substances involved in a particular reaction
C) Number of atoms/molecules of the reactants and products formed
D) Whether a particular reaction is actually feasible or not
90- The chemical formula of lead sulphate is
A) Pb₂SO₄
B) Pb(SO₄)₂
C) PbSO₄
D) Pb₂(SO₄)₃
91- Chemically, rust is
A) Hydrated ferrous
B) Only ferric oxide
C) Hydrated ferric oxide
D) None of these
92- Both CO₂ and H₂ gases are
A) Heavier than air
B) Colourless
C) Acidic in nature
D) Soluble in water
93- Which of the given gases can be used for storage of fresh samples of an oil for a long time?
A) Carbon dioxide or oxygen
B) Nitrogen or helium
C) Helium or oxygen
D) Nitrogen or oxygen
94- In the decomposition of lead (II) nitrate to give lead (II) oxide, nitrogen dioxide and oxygen gas, the coefficient of nitrogen dioxide (in the balanced equation) is
A) 1
B) 2
C) 3
D) 4
95- We store silver chloride in a dark coloured bottle because it is
A) A white solid
B) Undergoes redox reaction
C) To avoid action by sunlight
D) None of the above
96- Silver article turns black when kept in the open for a few days due to formation of
A) H₂S
B) AgS
C) AgSO₄
D) Ag₂S
97- When crystals of lead nitrate are heated strongly in a dry test tube
A) Crystals immediately melt
B) A brown residue is left
C) White fumes appear in the tube
D) A yellow residue is left
98- Which of the given products is formed when calcium oxide reacts with water?
A) Slaked lime
B) Carbon dioxide
C) Calcium oxide
D) Oxygen gas
99- What is the other name for quick lime?
A) Calcium hydroxide
B) Calcium oxide
C) Carbon dioxide
D) Sodium oxide
100- What is the chemical name for slaked lime?
A) Calcium carbonate
B) Calcium oxide
C) Calcium hydroxide
D) Carbon monoxide
101.The chemical formula of lead sulphate is
(a) Pb2SO4
(b) Pb(SO4)2
(c) PbSO4
(d) Pb2(SO4)3
102. Which information is not conveyed by a balanced chemical equation?
(a) Physical states of reactants and products
(b) Symbols and formulae of all the substances involved in a particular reaction
(c) Number of atoms/molecules of the reactants and products formed
(d) Whether a particular reaction is actually feasible or not
103. Chemically rust is
(a) hydrated ferrous oxide
(b) only ferric oxide
(c) hydrated ferric oxide
(d) none of these
104. Both CO2 and H2 gases are
(a) heavier than air
(b) colourless
(c) acidic in nature
(d) soluble in water
105. Which of the following gases can be used for storage of fresh sampel of an oil for a long time?
(a) Carbon dioxide or oxygen
(b) Nitrogen or helium
(c) Helium or oxygen
(d) Nitrogen or oxygen
106. The electrolytic decomposition of water gives H2 and O2 in the ratio of
(a) 1 : 2 by volume
(b) 2 : 1 by volume
(c) 8 : 1 by mass
(d) 1 : 2 by mass
107. In the decomposition of lead (II) nitrate to give lead (II) oxide, nitrogen dioxide and oxygen gas, the coefficient of nitrogen dioxide (in the balanced equation) is
a) 1
(b) 2
(c) 3
(d) 4
108. Fatty foods become rancid due to the process of
(a) oxidation
(b) corrosion
(c) reduction
(d) hydrogenation
109. We store silver chloride in a dark coloured bottle because it is
(a) a white solid
(b) undergoes redoc reaction
c) to avoid action by sunlight
(d) none of the above
110. Silver article turns black when kept in the open for a few days due to formation of
(a) H2S
(b) AgS
(c) AgSO4
(d) Ag2S
111. When crystals of lead nitrate are heated strongly in a dry test tube
a) crystals immediately melt
(b) a brown residue is left
(c) white fumes appear in the tube
(d) a yellow residue is left
112. Dilute hydrochloric acid is added to granulated zinc taken in a test tube. The following observations are recorded. Point out the correct observation.
(a) The surface of metal becomes shining
(b) The reaction mixture turns milky
(c) Odour of a pungent smelling gas is recorded
(d) A colourless and odourless gas is evolved
113. When carbon dioxide is passed through lime water,
a) calcium hydroxide is formed
(b) white precipitate of CaO is formed
c) lime water turns milky
(d) colour of lime water disappears.
114. When a magnesium ribbon is burnt in air, the ash formed is
(a) black
(b) white
(c) yellow
(d) pink
115. In which of the following, heat energy will be evolved?
a) Electrolysis of water
(b) Dissolution of NH4Cl in water
(c) Burning of L.P.G.
(d) Decomposition of AgBr in the presence of sunlight
116. Rancidity can be prevented by
(a) adding antioxidants
(b) storing food away from light
(c) keeping food in refrigerator
(d) all of these
117. The reaction of H2 gas with oxygen gas to form water is an example of
(a) combination reaction
(b) redox reaction
(c) exothermic reaction
(d) all of these reactions
119. The reaction in which two compound exchange their ions to form two new compounds is called
(a) displacement reaction
(b) combination reaction
(c) double displacement reaction
(d) redox reaction
120. On immersing an iron nail in CuSO4 solution for few minutes, you will observe
(a) no reaction takes place
(b) the colour of solution fades away
(c) the surface of iron nails acquire a black coating
(d) the colour of solution changes to green
121. An element X on exposure to moist air turns reddish-brown and a new compound Y is formed. The substance X and Y are
(a) X = Fe, Y = Fe2O3
(b) X = Ag, Y = Ag2S
(c) X = Cu, Y = CuO
(d) X = Al, Y = Al2O3
122. Sodium and chlorine are reacted and as a result, sodium chloride is formed which is also called table salt. What option gives the reactants and products of the reaction?
(a) reactants – sodium; products – chlorine
(b) reactants – sodium and table salt; products – chlorine
(c) reactants – tables salt; products – sodium and chlorine
(d) reactants – sodium and chlorine; products – sodium chloride
Correct Answer: Option (d)
123. Which of the following reactions can also be termed as thermal decomposition reaction?
(a) Combination Reaction
(b) Decomposition Reaction
(c) Displacement reaction
(d) Double displacement reaction
Correct Answer: Option (b)
Q124) The image shows some chemical reactions.
Which option identifies the reactants and products of the reactions?
Correct Answer: Option C
125) A student performs an experiment to form aluminium chloride from aluminium and chlorine.
Which options give the chemical equation of the reaction?
(a) Al + Cl2 → AlCl2
(b) 2Al + Cl2 → 2AlCl
(c) 2Al + 3Cl2 → 2AlCl3
(d) 3Al + 3Cl2 → 3AlCl3
Correct Answer: Option C
126. Give the ratio in which hydrogen and oxygen are present in water by
volume.
(a) 1:2
(b) 1:1
(c) 2:1
(d) 1:8
Correct Answer: Option (c)
127) A researcher adds barium hydroxide to hydrochloric acid to form a white-colored barium
chloride. Which option gives the balanced chemical equation of the reaction?
(a) HCl + Ba(OH)2 → BaCl2 + 2HOH
(b) 2HCl + Ba(OH)2 → BaCl2 + 2HOH
(c) 2HCl + Ba(OH)2 → BaH2 + 2HCl + O2
(d) HCl + 2Ba(OH) → 2BaCl2 + 2HOH + O2
Correct Answer: Option (b)
128. One of the following processes does not involve a chemical reaction, that is:
(a) Melting of candle wax when heated
(b) Burning of candle wax when heated
(c) Digestion of food in your stomach
(d) Ripening of banana
Correct Answer: Option (a)
129. A student writes a chemical equation of the reaction between carbon monoxide and hydrogen.
CO + 2H2 → CH3OH
How can the reaction be classified?
(a) The reaction is an example of a combination reaction as a compound separates into two
compounds.
(b) The reaction is an example of a decomposition reaction as a compound dissociates into
two compounds.
(c) The reaction is an example of a combination reaction as two compounds react to form a
single compound.
(d) The reaction is an example of a decomposition reaction as two compounds react to form
a single compound.
Correct Answer: Option (c)
130. The chemical formula of magnesium oxide is?
(a) MgO2
(b) Mg2O
(c) MgO
(d) Mg(OH)2
Correct Answer: Option (c)
131) A student learns that some products are formed as a result of combining two compounds while some compounds are formed as a result of dissociation of two compounds. The image shows two reactions.
Which reaction is an example of a combination reaction and a decomposition reaction?
(a) both the reactions are examples of combination reaction
(b) both the reactions are examples of a decomposition reaction
(c) reaction P is an example of a combination reaction while reaction Q is an example of a
decomposition reaction
(d) P is an example of a decomposition reaction while reaction Q is an example of a combination reaction
Correct Answer: Option C
132) From the following which one is the example of chemical reaction
(a) Grapes get fermented
(b) Breakdown of food
(c) Formation of curd
(d) All of the above
Correct Answer: Option (d) All of the above
133) A student adds lead and silver to two different test tubes containing an equal amount of copper sulphate solution. The student observes that the color of the solution in the test tube with lead changes. What explains the change in the colour of the solution?
(a) A displacement reaction takes place as lead replaces copper from the solution.
(b) A combination reaction takes place as lead combines with sulphate in the solution.
(c) decomposition reaction takes place as copper dissociates from sulphate in the solution.
(d) A double displacement reaction takes place as copper dissociates from sulphate and
lead combines with sulphate in the solution.
Correct Answer: Option (a)
134) Which of the reactions is used in black and white photography?
(a) Combination Reaction
(b) Decomposition Reaction
(c) Displacement reaction
(d) Oxidation reaction
Correct Answer: Option (b)
135) What happens when lead nitrate reacts with potassium iodide?
(a) They will not react
(b) Large amount of hydrogen release
(c) Yellow ppt of lead iodide and potassium nitrate will be produced
(d) Evolution of gas will occur
Correct Answer: Option (c)
136) The chemical reaction between potassium chloride and silver nitrate is given by the chemical
equation.
AgNO3 + KCl → AgCl + KNO3
What can be inferred from the chemical equation?
(a) silver nitrate and potassium undergo a decomposition reaction to form silver chloride
and potassium nitrate
(b) silver nitrate and potassium undergo a displacement reaction to form silver chloride
and potassium nitrate
(c) silver nitrate and potassium undergo a combination reaction to form silver chloride and
potassium nitrate
(d) silver nitrate and potassium undergo double displacement reaction to form silver
chloride and potassium nitrate
Correct Answer: Option (d)
137. Which of the following does show an oxidation reaction?
(a) Gain of oxygen
(b) Loss of oxygen
(c) Gain of hydrogen
(d) None of the above
Answer: (a) Gain of oxygen
138) The image shows a reaction between zinc and hydrogen.
Which option shows oxidation?
(a) Zn → Zn+2
(b) 2H+ → H2
(c) Zn+2 → Zn
(d) H2 → 2H+
Correct Answer: Option (a)
139. A chemical reaction has taken place in which of the following process?
(i) Ice melts into water
(ii) A wet shirt got dried in sunlight
(iii) A brown layer is formed over iron rod kept in air
(iv) Sugar getting dissolved in water
140. Which of the following is not a chemical Reaction?
(i) Formation of salt solution
(ii) Milk turns sour in hot weather
(iii) Burning of match stick
(iv) Contamination of food
141.A chemical reaction has taken place can be represented by which of the following condition?
(i) Evolution of gas
(ii) Heat released
(iii) Change in color
(iv) All the above
142. A chemical equation properly written has which of the following features?
(i)Temperature required
(ii) Should be balanced
(iii) Should have information regarding physical states
(iv) All the above
143. A Chemical equation should be balanced to
(i) Display conservation of energy
(ii) Display conservation of mass
(iii) To make equation attractive
(iv) All the above
144. An unbalanced chemical equation is equation written in
(i) Skeletal form
(ii) Proper form
(iii) Simple form
(iv) Unorganized form
145. A chemical equation is said to be balanced if number of
(i) Compounds are same in both side
(ii) Molecules are same in both side
(iii) Number of atoms is same in both side
(iv) Number of electrons are same in both side
145. When magnesium is burnt in air then
(i) Magnesium is reacting with oxygen
(ii) Magnesium is reacting with nitrogen
(iii) Magnesium is reacting with carbon
(iv) Magnesium is reacting with Carbon di oxide
146. Write values of a,b and c if following chemical reaction is balanced .
aMg + bO2 → cMgO
(i) a=1, b=2, c=2
(ii) a=2, b=1, c=2
(iii)a=2,b=2,c=2
(iv) a=1,b=2.c=1
146. Write values of a, b and c so that following chemical equation is balanced
aH2 + bO2 → cH2O
(i) a=2,b=1,c=2
(ii) a=1,b=1,c=2
(iii) a=1,b=2,c=1
(iv) a=2,b=2,c=1
147.Naveen Appeared In Class Test Where He Wrote Some Statements But He Confused To Know The Incorrect Statement. Would You Help Him To Know That?
[A]. All the decomposition reaction are endothermic reactions.
[B]. The decomposition of calcium carbonate is an endothermic reaction.
[C]. Photosynthesis is an endothermic reaction.
[D]. Electrolysis of water form hydrogen and oxygen is an exothermic reaction.
148.Nancy Is Writing Some Indicating Information About Chemical Equation. Choose The Correct One(S):
[A]. By indicating the physical state of the reactant and products.
[B]. By indicating the heat change take place in the reaction.
[C]. By indicating the condition under which their reaction takes place.
[D]. All the above.
149.Which Of The Following Is Not A Physical Change?
[A]. Boiling of water to give water vapour
[B]. Melting of ice to give water
[C]. Dissolution of salt in water
[D]. Combustion of Liquefied Petroleum Gas (LPG)
150.Which Of The Following Processes Involve Chemical Reactions?
[A]. A storing of oxygen gas under pressure in a gas cylinder.
[B]. Liquefaction of air.
[C]. Keeping petrol in china dish in an open.
[D]. Heating copper wire in the absence of air at high temperature.
151.In The Double Displacement Reaction Between Aqueous Potassium Iodide And Aqueous Lead Nitrate, A Yellow Precipitate Of Lead Iodide Is Formed. While Performing The Activity If Lead Nitrate Is Not Available, Which Of The Following Can Be Used In Place Of Lead Nitrate?
[A]. Lead sulphate (insoluble)
[B]. Lead acetate
[C]. Ammonium nitrate
[D]. Potassium sulphate
152. Before burning in air, the magnesium ribbon is cleaned by rubbing with a sand paper to:
a. Make the ribbon surface shinier
b. Remove the layer of magnesium oxide from the ribbon surface
c. Remove the layer of magnesium carbonate from the ribbon surface
d. Remove the moisture from the ribbon surface
153. In a chemical reaction between sulphuric acid and barium chloride solution the white precipitates formed are of:
a. Hydrochloric acid
b. Barium sulphate
c. Chlorine
d. Sulphur
154. The respiration process during which glucose undergoes slow combustion by combining with oxygen in the cells of our body to produce energy, is a kind of:
a. Exothermic process
b. Endothermic process
c. Reversible process
d. Physical process
155. A chemical reaction does not involve:
a. Formation of new substances having entirely different properties than that of the reactants
b. Breaking of old chemical bonds and formation of new chemical bonds
c. Rearrangement of the atoms of reactants to form new products
d. Changing of the atoms of on element into those of another element to form new products
156. One of the following processes does not involve a chemical reaction. That is:
a. Melting of candle wax when heated
b. Burning of candle wax when heated
c. Digestion of food in our stomach
d. Ripening of banana
157. It is necessary to balance a chemical equation in order to satisfy the law of:
a. Conservation of motion
b. Conservation of momentum
c. Conservation of energy
d. Conservation of mass
158. All the methods mentioned below can be used to prevent the food from getting rancid except:
i. Storing the food in the air-tight containers
ii. Storing the food in refrigerator
iii. Keeping the food in
159. The reaction between lead nitrate and potassium iodide present in aqueous solutions is an example of
(a) Decomposition Reaction (b) Displacement Reaction (c) Double Displacement Reaction (d) Neutralisation Reaction
160. Fatty foods become rancid due to the process of
(a) oxidation (b) corrosion (c) reduction (d) hydrogenation
161. Assertion: A lead nitrate on thermal decomposition gives lead oxide, brown coloured nitrogen dioxide and oxygen gas
. Reason: Lead nitrate reacts with potassium iodide to form yellow ppt of lead iodide and the reaction is double displacement as well as precipitation reaction.
162. Silver article turns black when kept in the open for a few days due to formation of (
a) H 2 S H2S (b) A g S AgS (c) A g S O 4 AgSO4 (d) A g 2 S Ag2S
163. Reaction of ‘magnesium’ with air is
(A) Exothermic reaction (B) Endothermic reaction (C) Reversible reaction (D) Substitution reaction
164. What type of chemical reactions take place when electricity is passed through water?
(a) Displacement (b) Combination (c) Decomposition (d) Double displacement
165. In an electrolytic cell where electrolysis is carried, anode has:
(a) Positive change (b) Negative charge (c) Connected to negative terminal of the battery (d) None of these is correct
166. On immersing an iron nail in C u S O 4 CuSO4 solution for few minutes, you will observe
(a) no reaction takes place (b) the colour of solution fades away (c) the surface of iron nails acquire a black coating (d) the colour of solution changes to green
167. Which of the given gases can be used for storage of fresh samples of an oil for a long time?
(A) Carbon dioxide or oxygen (B) Nitrogen or helium (C) Helium or oxygen (D) Nitrogen or oxygen
168. Rancidity can be prevented by
(a) adding antioxidants (b) storing food away from light (c) keeping food in refrigerator (d) all of these
169. In which of the following, heat energy will be evolved? (
a) Electrolysis of water (b) Dissolution of N H 4 C l NH4Cl in water (c) Burning of L.P.G. (d) Decomposition of AgBr in the presence of sunlight
170. What is the other name for quick lime?
(A) Calcium hydroxide (B) Calcium oxide (C) Carbon dioxide (D) Sodium oxide
171. Both C O 2 CO2 and H 2 H2 gases are
(A) Heavier than air (B) Colourless (C) Acidic in nature (D) Soluble in water
172. Which of the following are exothermic processes?
(i) Reaction of water with quick lime (ii) Dilution of an acid (iii) Evaporation of water (iv) Sublimation of camphor (crystals) (a) (i) and (ii) (b) (ii) and (iii) (c) (i) and (iv) (d) (iii) and (iv)
173. The reaction of acetylene and hydrogen in presence of heated nickel powder is called
: (a) Substitution (b) Dissociation (c) Addition (d) Decomposition.
174. Which of the following is not a physical change?
(a) Boiling of water to give water vapour (b) Melting of ice to give water (c) Dissolution of salt in water (d) Combustion of Liquefied Petroleum Gas (LPG)
175. What happens when dilute Sulphuric acid is added to Zn granules?
(a) Hydrogen gas and Zinc chloride are produced. (b) Chlorine gas and Zinc hydroxide are produced. (c) No reaction takes place. (d) Zinc salt and water are produced
. 176. A teacher gave two test tubes to the students, one containing water and the other containing sodium hydroxide. She asked them to identify the test tube containing sodium hydro
A.blue litmus
B.red litmus
C.soiudm carbonate
D.HCl
177. The substitution is characteristic of:
(a) Alkenes (b) Alkynes (c) Carbon monoxide (d) Paraffins.
178. What type of reaction is respiration
(a) Exothermic (b) Endothermic (c) Reduction reaction (d) Combination reaction
179..Addition of hydrogen in a substance in a reaction is known as___________ reaction.
180..In a ________ reaction two or more substances combine to form a new single substance.
181.Unbalanced reactions are also known as _________
183.Reactions in which heat is given out along with the products are called _________- reactions.
183.Reactions in which energy is absorbed are known as _________ reactions.
184.When as element displaces another element from its compound, a ________ reaction occurs.
185.Those reactions, in which two compounds react by an exchange of ions to form two new compounds, are called ________ reactions
186.Precipitation reactions produce __________ salts.
187.Reduction is the _________ of oxygen or gain of hydrogen.
188.The digestion of food in the body is an example of ____________ reaction.
189.The addition of oxygen to a substance is called __________.
190.When calcium carbonate is heated, it decomposes to give___________ and _________.
Solution
(a) Alkenes (b) Alkynes (c) Carbon monoxide (d) Paraffins.
178. What type of reaction is respiration
(a) Exothermic (b) Endothermic (c) Reduction reaction (d) Combination reaction
179..Addition of hydrogen in a substance in a reaction is known as___________ reaction.
180..In a ________ reaction two or more substances combine to form a new single substance.
181.Unbalanced reactions are also known as _________
183.Reactions in which heat is given out along with the products are called _________- reactions.
183.Reactions in which energy is absorbed are known as _________ reactions.
184.When as element displaces another element from its compound, a ________ reaction occurs.
185.Those reactions, in which two compounds react by an exchange of ions to form two new compounds, are called ________ reactions
186.Precipitation reactions produce __________ salts.
187.Reduction is the _________ of oxygen or gain of hydrogen.
188.The digestion of food in the body is an example of ____________ reaction.
189.The addition of oxygen to a substance is called __________.
190.When calcium carbonate is heated, it decomposes to give___________ and _________.
Solution
True or false
191.The number of atoms of each element is conserved in any chemical reaction.
192.Oxidation is the loss of electrons from a substance.
193.Reduction is the gain of electrons by a substance.
194.A complete chemical equation represents the reactants, products and their physical states symbolically.
195.A magnesium ribbon burns with a dazzling flame in air (oxygen) and changes into a white substance, magnesium oxide.
196.Rusting is a double decomposition reaction.
197.The reaction between nitrogen and hydrogen to give ammonia is an example of a combination reaction.
198.Action of heat on ferrous sulphate is an example of decomposition reaction.
199.The formation of Na+ and CI- ions from sodium and chlorine is an example of a redox reaction.
200. Assertion (A) : Decomposition of vegetable matter into compost is an example of exothermic reactions.
Reason (R) : Exothermic reaction are those reactions in which heat is evolved.
201. Assertion (A) : When HCl is added to zinc granules, a chemical reaction occurs.
Reason (R) : Evolution of a gas and change in colour indicate that the chemical reaction is taking place.
202. Assertion (A) : Calcium carbonate when heated gives calcium oxide and water.
Reason (R) : On heating calcium carbonate, decomposition reaction takes place.
203. Assertion (A) : Brown fumes are produced when lead nitrate is heated.
Reason (R) : Nitrogen dioxide gas is produced as a by product due to the decomposition of lead nitrate.
204. Assertion (A) : White silver chloride turns grey in sunlight.
Reason (R) : Decomposition of silver chloride in presence of sunlight takes place to form silver metal and chlorine gas.
205. Assertion (A): Pungent smelling gas is produced when sulphur burns in air.
Reason (R) : Sulphur trioxide is formed on reaction of sulphur with oxygen.
206. Assertion (A) : In a reaction of copper with oxygen, copper serves as a reducing agent.
Reason (R) : The substance which gains oxygen in a chemical reaction acts as a reducing agent.
207. Assertion (A) : In electrolysis of water, the volume of hydrogen liberated is twice the volume of oxygen formed.
Reason (R) : Water (H,0) has hydrogen and oxygen in the ratio of 1:2 by volume.
208. Assertion (A): Corrosion of iron is commonly known as rusting.
Reason (R) : Corrosion of iron occurs in presence of water and air.
209. Assertion (A) : The balancing of chemical equations is based on law of conservation of mass.
Reason (R) : Total mass of reactants is equal to total mass of products.
210. Assertion (A): In a balanced chemical equation, total mass of the reactants is equal to the total mass of the products.
Reason (R): Mass can neither be created nor destroyed during a chemical change.
211. Assertion (A): Iron articles are painted so as to prevent them from rusting.
Reason (R): When the surface of iron is coated with paint, its surface does not come in contact with oxygen and moisture therefore rusting does not take place
212.. Assertion (A) : Chemical reaction changes the physical and chemical state of a substance.
Reason (R) : When electric current is passed through water (liquid), it decomposes to produce hydrogen and
oxygen gases.
213. Assertion (A): When calcium carbonate is heated, it decomposes to give calcium oxide and carbon dioxide.
Reason (R): The decomposition reaction takes place on application of heat, therefore, it is an endothermic reaction.
214. Assertion (A): Zinc reacts with sulphuric acid to form zinc sulphate and hydrogen gas and it is a displacement reaction.
Reason (R): Zinc reacts with oxygen to form zinc oxide
215. Assertion (A): Chips manufacturers usually Ilush bags of chips with gas such as nitrogen to prevent the chips from getting oxidised.
Reason (R): This increase the taste ot the chips and helps in their digestion.
216. Assertion (A): Exposure of silver chloride to sunlight for a long duration turns grey due to the formation of silver by decomposition of silver chloride.
Reason (R): In this process, sublimation of silver chloride takes place
217. Assertion (A): Rusting of iron metal is the most common form of corrosion.
Reason (R): The effect of rusting of iron can be reversed if they are left open in sunlight.
218. Assertion (A): AgBr is used on photographic and X-ray film.
Reason (R): AgBr is photosensitive and changes to Ag and bromine in presence of sunlight and undergoes
decomposition reaction.
219. Assertion (A): Magnesium ribbon keeps on burning in atmosphere of nitrogen.
Reason (R) : Magnesium reacts with nitrogen to form magnesium nitride and this reaction is combination reaction.
220. Assertion (A): A lead nitrate on thermal decomposition gives lead oxide, brown coloured nitrogen dioxide and oxygen gas.
Reason (R): Lead nitrate reacts with potassium iodide to form yellow ppt. of lead iodide and the reaction is double displacement as well as precipitation reaction.
221. Assertion: Chemical reaction changes the physical and chemical state of a substance.
Reason: When electric current is passed through water (liquid), it decomposes to produce hydrogen and oxygen gases.
222. Assertion: In a balanced chemical equation, total mass of the each element towards reactant side= total mass of the same element towards product side.
Reason: Mass can neither be created nor destroyed during a chemical change.
223. Assertion: When calcium carbonate is heated, it decomposes to give calcium oxide and carbon dioxide.
Reason: The decomposition reaction takes place on application of heat, therefore, its and endothermic reaction.
224. Assertion: Chips manufacturers usually flush bags of chips with gas such as nitrogen to prevent the chips from getting oxidised.
Reason: This increase the taste of the chips and helps in their digestion.
225. Assertion: Rusting of iron metal is the most common form of corrosion.
Reason: The effect of rusting of iron can be reversed if they are left open in sunlight.
226. Name and state the law which is kept in mind while we balance a chemical equation.
a) Law of Equal Proportion
(b) Law of Conservation of Mass
(c) Daltons Law
(d) Avogadro’s Law
227. What is breaking and making of bonds in chemical reaction called?
(a) Chemical Reaction
(b) Chemical Equation
(c) Chemical Bonding
(d) Chemical Equilibrium
228. A red-brown gas is released along with O2 and lead oxide on heating lead nitrate. It is an example of
(a) combination reaction
(b) oxidation reaction
(c) decomposition reaction
(d) reduction reaction
229.. What are the coefficients of the correctly balanced equation?
?Fe2O3 + ?CO → ?Fe+ ?CO2
(a)0, 2, 2,3
(b) 1,3,2,3
(c)1,2,2,2
(d)2,6, 4,3
230· Burning of a candle is a
(a) physical change
(b) a chemical change
(c) slow change
(d) gaseous change
231.A substance which oxidises itself and reduces other is
known as -
(a) oxidising agent (b) reducing agent
(c) both of these (d) none of these
232. Which of the following reactions involves the combination of two elements?
(a) CaI CO CaCO + 2 3 "
(b) 4 2 Na O Na O + 2 2 "
(c) s + o2 gives SO 2
233. When hydrogen sulphide gas is passed through a blue
solution of copper sulphate, a black precipitate of copper sulphide is obtained and the sulphuric acid so
formed remains in the solution. The reaction is an
example of-
(a) a combination reaction
(b) a displacement reaction
(c) a decomposition reaction
(d) a double decomposition reaction
234. Which of the following is a physical change?
(a) Formation of curd from milk
(b) Ripening of fruits
(c) Getting salt from sea water
(d) Burning of wood
235. What happens when copper rod is dipped in iron sulphate solution?
(a) Copper displaces iron
(b) Blue colour of copper sulphate solution is obtained
(c) No reaction takes place
(d) Reaction is exothermic
236. A student added dilute HCl to a test tube containing
zinc granules and made following observations :
(a) the zinc surface became dull and black
(b) a gas evolved which burnt with a pop sound
(c) the solution remained colourless
(d) the solution becomes green in colour
237. A dilute solution of sodium carbonate was added
to two test tubes - one containing dil HCl (a) and
the other containing dilute NaOH(b). The correct
observation was-
(a) a brown coloured gas liberated in test tube A
(b) a brown coloured gas liberated in test tube B
(c) a colourless gas liberated in test tube A
(d) a colourless gas liberated in test tube B
238. A balanced chemical equation is in accordance with-
(a) Avogadro’s law
(b) law of multiple proportion
(c) law of conservation of mass
(d) law of gaseous volumes
239. Zn + H 2SO 4 gives dil ZnSO4 + H20
Above reaction is -
(a) decomposition reaction
(b) single displacement reaction
(c) combination reaction
(d) synthesis reaction
240. The reaction in which two compounds exchange their
ions to form two new compounds is -
(a) a displacement reaction
(b) a decomposition reaction
(c) an isomerization reaction
(d) a double displacement reaction
241. A redox reaction is one in which-
(a) both the substance are reduced
(b) both the substance are oxidised
(c) an acid is neutralised by the base
(d) one substance is oxidised while the other is reduced
242. When the gases sulphur dioxide and hydrogen sulphide mix in the presence of water, the reaction is
S02 + H2s gives s + H2O " . Here hydrogen sulphide is
acting as -
(a) an oxidising agent (b) a reducing agent
(c) a dehydrating agent (d) a catalyst
243. CuO + H 2 gives H2 O + Cu , reaction is an example of -
(a) redox reaction
(c) s + o2 gives SO 2
233. When hydrogen sulphide gas is passed through a blue
solution of copper sulphate, a black precipitate of copper sulphide is obtained and the sulphuric acid so
formed remains in the solution. The reaction is an
example of-
(a) a combination reaction
(b) a displacement reaction
(c) a decomposition reaction
(d) a double decomposition reaction
234. Which of the following is a physical change?
(a) Formation of curd from milk
(b) Ripening of fruits
(c) Getting salt from sea water
(d) Burning of wood
235. What happens when copper rod is dipped in iron sulphate solution?
(a) Copper displaces iron
(b) Blue colour of copper sulphate solution is obtained
(c) No reaction takes place
(d) Reaction is exothermic
236. A student added dilute HCl to a test tube containing
zinc granules and made following observations :
(a) the zinc surface became dull and black
(b) a gas evolved which burnt with a pop sound
(c) the solution remained colourless
(d) the solution becomes green in colour
237. A dilute solution of sodium carbonate was added
to two test tubes - one containing dil HCl (a) and
the other containing dilute NaOH(b). The correct
observation was-
(a) a brown coloured gas liberated in test tube A
(b) a brown coloured gas liberated in test tube B
(c) a colourless gas liberated in test tube A
(d) a colourless gas liberated in test tube B
238. A balanced chemical equation is in accordance with-
(a) Avogadro’s law
(b) law of multiple proportion
(c) law of conservation of mass
(d) law of gaseous volumes
239. Zn + H 2SO 4 gives dil ZnSO4 + H20
Above reaction is -
(a) decomposition reaction
(b) single displacement reaction
(c) combination reaction
(d) synthesis reaction
240. The reaction in which two compounds exchange their
ions to form two new compounds is -
(a) a displacement reaction
(b) a decomposition reaction
(c) an isomerization reaction
(d) a double displacement reaction
241. A redox reaction is one in which-
(a) both the substance are reduced
(b) both the substance are oxidised
(c) an acid is neutralised by the base
(d) one substance is oxidised while the other is reduced
242. When the gases sulphur dioxide and hydrogen sulphide mix in the presence of water, the reaction is
S02 + H2s gives s + H2O " . Here hydrogen sulphide is
acting as -
(a) an oxidising agent (b) a reducing agent
(c) a dehydrating agent (d) a catalyst
243. CuO + H 2 gives H2 O + Cu , reaction is an example of -
(a) redox reaction
(b) synthesis reaction
(c) neutralisation
(d) analysis reaction
244. In the following equations :
Na 2CO 3 +x HCl gives NaCl +CO2+ H20 the value of
x is-
(a) 1 (b) 2 (c) 3 (d) 4
245. In the equation, NaOH +HNO3 gives NaNO3 + H2 O nitric acid is acting as-
(a) an oxidising agent (b) an acid
(c) a nitrating agent (d) a dehydrating agent
246. Fe2 O 3 + Al goves Al 2O3 + Fe
The above reaction is an example of a-
(a) combination reaction
(b) double displacement reaction
(c) decomposition reaction
(d) displacement reaction
247. White silver chloride in sunlight turns to-
(a) grey (b) yellow(c) remain white (d) red
248. Black and white photography uses-
(a) decomposition of silver chloride
(b) decomposition of silver bromide
(c) both
(d) none of these
249. When copper powder is heated it gets coated with-
(a) black copper oxide (b) yellow copper oxide
(c) red copper oxide (d) None of these
250. Combination of phosphorus and oxygen is an example
of -
(a) oxidation (b) reduction
(c) rancidity (d) None of these
251. To indicate the presence of gaseous reactant or
product, we use the symbol
(a) (Product) g or (Reactant) g
(b) (Product)- or (Reactant)-
(c) (Product). or (Reactant).
(d) Both (a) and (b)
252.Ca (NO3)2 on heating gives CaO, NO2 , 02
244. In the following equations :
Na 2CO 3 +x HCl gives NaCl +CO2+ H20 the value of
x is-
(a) 1 (b) 2 (c) 3 (d) 4
245. In the equation, NaOH +HNO3 gives NaNO3 + H2 O nitric acid is acting as-
(a) an oxidising agent (b) an acid
(c) a nitrating agent (d) a dehydrating agent
246. Fe2 O 3 + Al goves Al 2O3 + Fe
The above reaction is an example of a-
(a) combination reaction
(b) double displacement reaction
(c) decomposition reaction
(d) displacement reaction
247. White silver chloride in sunlight turns to-
(a) grey (b) yellow(c) remain white (d) red
248. Black and white photography uses-
(a) decomposition of silver chloride
(b) decomposition of silver bromide
(c) both
(d) none of these
249. When copper powder is heated it gets coated with-
(a) black copper oxide (b) yellow copper oxide
(c) red copper oxide (d) None of these
250. Combination of phosphorus and oxygen is an example
of -
(a) oxidation (b) reduction
(c) rancidity (d) None of these
251. To indicate the presence of gaseous reactant or
product, we use the symbol
(a) (Product) g or (Reactant) g
(b) (Product)- or (Reactant)-
(c) (Product). or (Reactant).
(d) Both (a) and (b)
252.Ca (NO3)2 on heating gives CaO, NO2 , 02
.are respectively
(a) 2, 1, 3, 2 (b) 2, 2, 4, 1
(c) 2, 2, 2, 1 (d) 1, 2, 4, 1
253.Which of the following reaction is characterised by the
yellow colour of product?
(a) Zn + H 2SO4 gives ZnSO4 + H2
(a) 2, 1, 3, 2 (b) 2, 2, 4, 1
(c) 2, 2, 2, 1 (d) 1, 2, 4, 1
253.Which of the following reaction is characterised by the
yellow colour of product?
(a) Zn + H 2SO4 gives ZnSO4 + H2
(b) Na2 CO 3 + H2 SO4 gives Na2 SO4 + H 2O + CO2
(c) Pb3 O 4 gives PbO + O 2
(d) kclo3 gives kcl + o2
254. Which one of the following involve a chemical reaction?
(a) Evaporation of water
(b) Storing on nitrogen gas under pressure
(c) Keeping petrol in a China dish in open
(d) Heating magnesium wire in the presence of air at
high temperature
255. Ethane ( ) C H2 6 on complete combustion gave CO2 and
water. It shows that the results are in accordance with
the law of conservation of mass. Then, the coefficient
of oxygen is equal to
(a) 3 (b) 5/2 (c) 2 (d) 7/2
256. A powdered salt ( ) X in a dry test tube was heated that evolves brown fumes of nitrogen dioxide and a
yellow residue of lead oxide is also formed. The salt
( ) X is
(a) MgSO3 (b) Pb NO ( )3 2
(c) ( ) NH SO 42 4 (d) CaCO3
257. A reddish brown coloured metal used in electric wires, when powdered and heated strongly in an open China
dish, its colour turns black. When hydrogen gas is passed over this black substances, it regain its original
colour. Based on this information, the metal and black
coloured substances are
(a) copper and copper nitrate
(b) silver and silver oxide
(c) copper and copper oxide
(d) aluminium and aluminium oxide
258. When dilute sulphuric acid is added to pieces of iron sulphide, hydrogen sulphide gas is produced
and soluble ferrous sulphate is formed. The type of
chemical reaction involved is
(a) decomposition reaction
(b) combination reaction
(c) displacement reaction
(d) double displacement reaction
259. Following reaction is used for the preparation of oxygen gas in the laboratory.
Kclo3 gives kcl + o2 Catalyst Heat
Which of the following statement ( )s is (are) correct about the reaction?
(a) It is a decomposition reaction and endothermic in nature.
(b) It is a combination reaction.
(c) It is a decomposition reaction and accompanied
by the release of heat.
(d) It is a photochemical decomposition reaction and
exothermic in nature.
Ans : (a) It is a decomposition reaction and
endothermic in nature.
The given reaction is a decomposition reaction and
takes place on absorption of h
260.A metal ‘M ’ reacts with an acid according to the
equation.
M M H H 3 + + $ 2 + +
Which of the following is correct for metal M ?
(a) Calcium (b) Aluminium
(c) Barium (d) Potassium
Ans : (c) Barium
261. Balancing of H-atoms : Multiply H+ on LHS by 2.
M + 2H+ M H 3 $ + 2 +
2. Balancing charge : Multiply H2 + by 3 and M 3+ by
2 so that charge on each side is +6.
3. Re-balancing of H-atoms: Multiply H2 on RHS by
3
M + 6H+ 2 3 M H 3 $ + 2 +
4. Balancing of M -atoms: Multiply M LHS by 2
2 6 M + H+ 2 3 M H 3 $ + 2 +
This is the required balanced equation and the metal
is aluminium ( ). M
262. When calcium carbonate is heated, it decomposes to
from .......... and .......... gas.
263.. Precipitation reactions produce .......... salts.
264. Electrolysis of water is a .......... decomposition reaction.
265. Reactions in which energy is absorbed are known as
.......... reactions.
266. The new substances produce in a reaction are called as ..........
267. The reaction of sodium sulphate and barium chloride results in the formation of white precipitate of ..........
268. Two different atoms or groups of atoms (ions) are exchanged in .......... reactions.
269. Precipitation reactions
produce ......... salts.
270. Reduction is the .......... of oxygen or gain of hydrogen.
271. The addition of oxygen to a substance is called ..........
272. The digestion of food in the body is an example of ......... reaction
273. The addition of oxygen to a substance is called ..........
274. When calcium carbonate is heated, it decomposes to
give .......... and ..........
275. In a .......... reaction two or more substances combine to form a new single substance.
276. Reactions in which heat is given out along with the products are called .......... reactions.
277. When an element displaces another element from its
compound, a .......... reaction occurs.
278. A complete chemical equation represents the reactants,
products and their physical states symbolically.
279. The reaction of nitrogen and hydrogen gives ammonia. This is an example of a decomposition reaction.
280. A magnesium ribben burns with a dazzling flame in air (oxygen) and changes into a white substance,
magnesium oxide.
281. Rusting is doubledecomposition reaction.
282. A chemical cannot be reversed.
283. The number of atoms of each element is conserved in any chemical reaction.
284. Oxidation is the loss of electrons from a substance.The term ‘aqueous’ represents water as solvent.
285. Rusting of iron and rancidity are caused due to oxidation.
286. Reduction is the gain of electrons by a substance.
287. The formation of Cu and H O2 the reaction of copper oxide is an example of a redox reaction.
288. Curdling of milk is a physical change.
289. The reaction between nitrogen and hydrogen to give ammonia is an example of a combination reaction.
290. For word-equations, we do no need to know the formulae for the chemicals involved but in symbol-
equations we do.
291. Action of heat on ferrous sulphate is an example of
decomposition
292.Assertion : Stannous chloride is a powerful oxidising agent which oxidises mercuric chloride to mercury.
Reason : Stannous chloride gives grey precipitate with
mercuric chloride, but stannic chloride does not do so.
C
293. Assertion : Corrosion of iron is commonly known as rusting.
Reason : Corrosion of iron occurs in presence of water
and air.
B
294
. Assertion : In a reaction.
Zn + CuSO4 gives ZnSO4 + Cu is a reductant but itself get oxidized.
Reason : In a redox reaction, oxidant is reduced by accepting electrons and reductant is oxidized by losing
electrons.
295. Assertion : A reducing agent is a substance which can
either accept electron.
Reason : A substance which helps in oxidation is known as reducing agent.
296. Assertion : The balancing of chemical equations is
based on law of conservation of mass.
Reason : Total mass of reactants is equal to total mass
of products.
297. Assertion (A) : Carbon dioxide turns lime water milky.
Reason (R) : Carbon dioxide sullies the water.
Sullies means adulterated
298. Assertion (A) : A chemical reaction becomes faster at
higher temperatures.
Reason (R) : At higher temperatures, molecular motion becomes more rapid.
299. Assertion (A) : Sodium metal is stored under Kerosene.
Reason (R) : Metallic sodium melts when exposed to air.
300.. Assertion (A) : To dilute sulphuric acid, acid is added
to water and not water to acid.
Reason (R) : Specific heat of water is quite large.
A
301. Assertion(A) : Calcium corbonate when heated gives calcium oxide and water.
Reason (R) : On heating calcium carbonate, decomposition reaction takes place.
302. Assertion(A) : Brown fumes are produced when lead
nitrate is heated.
Reason (R) : Nitrogen dioxide gas is produced as a
by product due to the decomposition of lead nitrate.
303. Assertion(A) : White silver chloride turns grey in
sunlight.
Reason (R) : Decomposition of silver chloride in presence of sunlight takes place to form silver metal
and chlorine gas.
304. Assertion(A) : Pungent smelling gas is produced when sulphur burns in air.
Reason (R) : Sulphur trioxide is formed on reaction of sulphur with oxygen.
2305. Assertion(A) : In a reaction of copper with oxygen,copper serves as a reducing agent.
Reason (R) : The substance which gains oxygen in a chemical reaction is a reducing agents.
306. Assertion : The following chemical equation,
2C H O CO H O 2
7 66 2 + + $4 3 2 2
is a balanced chemical equation.
Reason : In a balanced chemical equation, the total number of atoms of each element may or may not
equal on both side of the equation.
307.
Assertion : Fe2O3 +Al gives Al 2O 3 +Fe
The above chemical equation is an example of
displacement reaction.
Reason : Aluminium being more reactive than iron,
displaces Fe from its oxide.
308. Assertion : In the following chemical equation,
CuO + Zn gives ZnO + Cu
is getting oxidised and copper oxide is getting reduced.
Reason : The process in which oxygen is added to asubstance is called oxidation whereas the process in
which oxygen is removed from a substance is called
reduction.
309. Assertion : Quicklime reacts vigorously with water
releasing a large amount of heat.
Reason : The above chemical reaction is an exothermic
reaction.
310. Assertion : Photosynthesis is considered as an endothermic reaction.
Reason : Energy gets released in the process of photosynthesis.
Reason : The process in which oxygen is added to asubstance is called oxidation whereas the process in
which oxygen is removed from a substance is called
reduction.
309. Assertion : Quicklime reacts vigorously with water
releasing a large amount of heat.
Reason : The above chemical reaction is an exothermic
reaction.
310. Assertion : Photosynthesis is considered as an endothermic reaction.
Reason : Energy gets released in the process of photosynthesis.
Question 311
Which of the following reactions involves the combination of two elements :-
(a)CaO + CO2 -> CaCO3
(b)4Na + O2 -> 2Na2O
(c)SO2 +(1/2)O2 -> SO3
(d)NH3 + HCI -> NH4CI
Question 312
When hydrogen sulphide gas is passed through a blue solution of copper sulphate, a black precipitate of copper sulphate is obtained and the sulphuric acid so formed remains in the solution. The reaction is an example of :-
(a)A combination reaction
(b)A displacement reaction
(c)A decomposition reaction
(d)A double decomposition reaction
Question 313
What happens when copper rod is dipped in iron sulphate solution :-
(a)Copper displaces iron
(b)Blue color of copper sulphate solution is obtained
(c)No reaction takes place
(d)Reaction is exothermic
Question 314
A student added dilute HCI to a test tube containing zinc granules and made following observations :-
(a)The zinc surface became dull and black
(b)A gas evolved which burnt with a pop sound
(c)The solution remained colorless
(d)The solution becomes green in color.
Question 315
A dilute solution of sodium carbonate was added to two test tubes one containing dilute HCI (A) and the other containing dilute NaOH (B). the correct observation was :-
(a)A brown colored gas liberated in test tube A
(b)A brown colored gas liberated in test tube B
(c)A colorless gas liberated in test tube A
(d)A colorless gas liberated in test tube B
Question 316
A balanced chemical equation is in accordance with
(a)Avogadro’s law
(b)Law of multiple proportion
(c)Law of conservation of mass
(d)Law of gaseous volumes
Question 317
The equation
Cu + xHNO3 -> Cu(NO3)2 + yNO2 + 2H2O
The values of x and y are
(a)3 and 5
(b)8 and 6
(c)4 and 2
(d)7 and 1
Question 318
Zn + H2SO4(dil) ->ZnSO4 + H2
Above reaction is
(a)Decomposition reaction
(b)Single displacement reaction
(c)Combination reaction
(d)Synthesis reaction
Question 319.
The reaction in which two compounds exchange their ions to form two new compounds is
(a)A displacement reaction
(b)A decomposition reaction
(c)An isomerization reaction
(d)A double displacement reaction
Question 320
When the gases sulphur dioxide and hydrogen sulphide mix in the presence of water, the reaction is
SO2 + 2H2S -> 2H2O + 3S. here hydrogen sulphide is acting as
(a)An oxidizing agent
(b)A reducing agent
(c)A dehydrating agent
(d)A catalyst
Question 321
CuO + H2 ->H2O + Cu, reaction is an example of
(a)Redox reaction
(b)Synthesis reaction
(c)Neutralization
(d)Analysis reaction
Question 322
A substance which oxidized itself and reduces other is known as
(a)Oxidizing agent
(b)Reducing agent
(c)Both of these
(d)None of these
Question 323
A redox reaction is one in which
(a)Both the substance are reduced
(b)Both the substance are oxidized
(c)An acid is neutralized by the base
(d)One substance is oxidized while the other is reduced
Question 324
In the following equation:
Na2CO3 + xHCI -> 2NaCI +CO2 + H2O, the value of x is
(a)1
(b)2
(c)3
(d)4
Question 325
In the equation, NaOH + HNO3 -> NaNO3 + H2O nitric acid is acting as
(a)An oxidizing agent
(b)An acid
(c)A nitrating agent
(d)A dehydrating agent
Question 326
Fe2O3+ 2AI2O3 + 2Fe
The above reaction is an example of a
(a)Combination reaction
(b)Double displacement reaction
(c)Decomposition reaction
(d)Displacement reaction
Question 327
White silver chloride in sunlight turns to
(a)Grey
(b)Yellow
(c)Remain white
(d)Red
Question 328
Black and white photography uses
(a)Decomposition of silver chloride
(b)Decomposition of silver bromide
(c)Both
(d)None of these
Question 329
When copper powder is heated it gets coated with
(a)Black copper oxide
(b)Yellow copper oxide
(c)Red copper oxide
(d)None of these
Question 330
Combination of phosphorus and oxygen is an example of
(a)Oxidation
(b)Reduction
(c)Rancidity
(d)None of these
Question 331
Rusting of an iron is an example of
a)Reduction
b)Ionization
c)Oxidation
d)Dissociation
Question 322
Which of the following does not corrode when exposed to the atmosphere-
(a)Iron
(b)Copper
(c)Gold
(d)Silver
Question 323.
Take about 1.0g CaCO3 in a test tube. Heat it over a flame, when a colorless gas comes out. The reaction is called a
(a)Decomposition reaction
(b)Displacement reaction
(c)Double decomposition reaction
(d)Double displacement reaction
Question 324.
Hydrogen sulphide (H2S) is a strong reducing agent. Which of the following reactions shows its reducing action
(a)Cd(NO3)2 + H2S -> CdS + 2HNO3
(b)CuSO4 + H2S -> CuS + H2SO4
(c)2FeCl3 + H2S -> 2FeCl2 + 2HCI + S
(d)Pb(NO3)2 +H2S -> PbS + 2CH3COOH
Question 325.
When P reacts with caustic soda, the products are PH3 and NaH2PO2. This reaction is an example of
(a)Oxidation
(b)Reduction
(c)Oxidation and reduction (redox)
(d)Neutralization
Question 326.
2CuI-> Cu + CuI2, the reaction is
(a)Redox
(b)Neutralization
(c)Oxidation
(d)Reduction
Question 327.
When copper turning are added to silver nitrate solution, a blue coloured solution is formed after some time. It is because, copper
(a)Displaces silver from the solution
(b)Forms a blue colored complex with AgNO3
(c)Is oxidized to Cu2+Cu2+
(d)Is reduced to Cu2+Cu2+
Question 328.
Zn2+ (aq) +2e -> Zn(s). this is
(a)Oxidation
(b)Reduction
(c)Redox reaction
(d)None of these
Q329. Assertion (A) : Decomposition of vegetable matter into compost is an example of exothermic reactions.
Reason (R) : Exothermic reaction are those reactions in which heat is evolved.
330. Assertion (A) : When HCl is added to zinc granules, a chemical reaction occurs.
Reason (R) : Evolution of a gas and change in colour indicate that the chemical reaction is taking place.
341. Assertion (A) : Calcium carbonate when heated gives calcium oxide and water.
Reason (R) : On heating calcium carbonate, decomposition reaction takes place.
342. Assertion (A) : Brown fumes are produced when lead nitrate is heated.
Reason (R) : Nitrogen dioxide gas is produced as a by product due to the decomposition of lead nitrate.
343. Assertion (A) : White silver chloride turns grey in sunlight.
Reason (R) : Decomposition of silver chloride in presence of sunlight takes place to form silver metal and chlorine gas.
344. Assertion (A): Pungent smelling gas is produced when sulphur burns in air.
Reason (R) : Sulphur trioxide is formed on reaction of sulphur with oxygen.
345. Assertion (A) : In a reaction of copper with oxygen, copper serves as a reducing agent.
Reason (R) : The substance which gains oxygen in a chemical reaction acts as a reducing agent.
346 Assertion (A) : In electrolysis of water, the volume of hydrogen liberated is twice the volume of oxygen formed.
Reason (R) : Water (H,0) has hydrogen and oxygen in the ratio of 1:2 by volume.
347. Assertion (A): Corrosion of iron is commonly known as rusting.
Reason (R) : Corrosion of iron occurs in presence of water and air.
348 Assertion (A) : The balancing of chemical equations is based on law of conservation of mass.
Reason (R) : Total mass of reactants is equal to total mass of products.
349.. Assertion (A): In a balanced chemical equation, total mass of the reactants is equal to the total mass of the products.
Reason (R): Mass can neither be created nor destroyed during a chemical change.
350.. Assertion (A): Iron articles are painted so as to prevent them from rusting.
Reason (R): When the surface of iron is coated with paint, its surface does not come in contact with oxygen and moisture therefore rusting does not take place.
351 . Assertion (A) : Chemical reaction changes the physical and chemical state of a substance.
Reason (R) : When electric current is passed through water (liquid), it decomposes to produce hydrogen and
oxygen gases.
352. Assertion (A): When calcium carbonate is heated, it decomposes to give calcium oxide and carbon dioxide.
Reason (R): The decomposition reaction takes place on application of heat, therefore, it is an endothermic reaction.
353 Assertion (A): Zinc reacts with sulphuric acid to form zinc sulphate and hydrogen gas and it is a displacement reaction.
Reason (R): Zinc reacts with oxygen to form zinc oxide
354. Assertion (A): Chips manufacturers usually Ilush bags of chips with gas such as nitrogen to prevent the chips from getting oxidised.
Reason (R): This increase the taste ot the chips and helps in their digestion.
355. Assertion (A): Exposure of silver chloride to sunlight for a long duration turns grey due to the formation of silver by decomposition of silver chloride.
Reason (R): In this process, sublimation of silver chloride takes place.
356. Assertion (A): Rusting of iron metal is the most common form of corrosion.
Reason (R): The effect of rusting of iron can be reversed if they are left open in sunlight.
357. Assertion (A): AgBr is used on photographic and X-ray film.
Reason (R): AgBr is photosensitive and changes to Ag and bromine in presence of sunlight and undergoes
decomposition reaction.
358. Assertion (A): Magnesium ribbon keeps on burning in atmosphere of nitrogen.
Reason (R) : Magnesium reacts with nitrogen to form magnesium nitride and this reaction is combination reaction.
359.. Assertion (A): A lead nitrate on thermal decomposition gives lead oxide, brown coloured nitrogen dioxide and oxygen gas.
Reason (R): Lead nitrate reacts with potassium iodide to form yellow ppt. of lead iodide and the reaction is double displacement as well as precipitation reaction.
CASE STUDY
Those reactions in which two compounds react by an exchange of ions to form two new compounds are called double displacement reactions. A double displacement reaction usually occurs in solution and one of the products, being insoluble, precipitate out (separates as a solid). Any reaction in which an insoluble solid (called precipitate) is formed that separates from the solution is called a precipitation reaction. The reaction in which acid or acidic oxide reacts with base or basic oxide to form salt and water is called neutralisation reaction.
For example,
2NaOH + H2SO4⟶Na2SO4 + H2O
360.When hydrogen sulphide gas is passed through a blue solution of copper sulphate, a black precipitate of copper sulphide is obtained and the sulphuric acid so formed remains in the solution. The reaction is an example of a
(a) combination reaction
(b) displacement reaction
(c) decomposition reaction
d) double displacement reaction
(361i) Which of the following is not a double displacement reaction?
(a) AgNO3(aq)+NaCl(aq)⟶AgCl(s)+NaNO3(aq)
(b) Zn(s)+H2SO4(aq)⟶ZnSO4(aq)+H2(g)
362. Barium chloride on reaction with ammonium sulphate forms barium sulphate and ammonium chloride. Which of the following correctly represents the type of the reaction involved?
(I) Displacement reaction
(II) Precipitation reaction
(III) Combination reaction
(IV) Double displacement reaction
(a) (I) only
(b) (II) only
(c) (III) and (IV) only
(d) (II) and ( V) onlly
363. Identify A in the following reaction.
AlCl3(aq)+3NH4OH(aq)⟶A+3NH4Cl(aq)AlCl3(aq)+3NH4OH(aq)⟶A+3NH4Cl(aq)
(a) AI(OH)3(b) Al2 O3(c) AIH3(d) AIN
(a) AI(OH)3(b) Al2 O3(c) AIH3(d) AIN
364. Consider the following reaction,
BaCl2+Na2SO4⟶BaSO4+2NaCl
identify the precipitate in the reaction,
(a) BaCl2(b) BaSO4(c) Na2sO4
Case study
• The earlier concept of oxidation and reduction is based on the addition or removal of oxygen or hydrogen elements so, in terms of oxygen and hydrogen, oxidation is addition of oxygen to a substance and removal of hydrogen from a substance. On the other hand, reduction is addition of hydrogen to a substance and removal of oxygen from a substance. The substance which gives oxygen to another substance or removes hydrogen from another substance in an oxidation reaction is known as oxidising agent, while the substance which gives hydrogen to another substance or removes oxygen from another substance in a reduction reaction is known as reducing agent. For example,
(365 A redox reaction is one in which
(a) both the substances are reduced(b) both the substances are oxidised(c) an acid is neutralised by the base(d) one substance is oxidised while the other is reduced.
(366 In the reaction, H2 S+Cl2⟶S+2HClH2 S+Cl2⟶S+2HCl
(a) H2S is the reducing agent.(b) HCI is the oxidising agent.(c) H2S is the oxidising agent.(d) Cl2 is the reducing agent.
(367 Which ofthe following processes does not involve either oxidation or reduction?
(a) Formation of slaked lime from quick lime.(b) Heating mercuric oxide.(c) Formation of manganese chloride from manganese oxide (MnO2).(d) Formation of zinc from zinc blende.
(368 Mg+CuO⟶MgO+Cu (iv) Mg+CuO⟶MgO+Cu
Which of the following is wrong relating to the above reaction?
(a) CuO gets reduced(b) Mg gets oxidised. (c) CuO gets oxidised.(d) It is a redox reaction.
(369.Identify the correct oxidising agent and reducing agent in the following reaction.
Fe2O3+2Al⟶2Fe+Al2O3Fe2O3+2Al⟶2Fe+Al2O3
(a) AI- Oxidising agent, Fe2O3 - Reducing agent(
Which of the following reactions involves the combination of two elements :-
(a)CaO + CO2 -> CaCO3
(b)4Na + O2 -> 2Na2O
(c)SO2 +(1/2)O2 -> SO3
(d)NH3 + HCI -> NH4CI
Question 312
When hydrogen sulphide gas is passed through a blue solution of copper sulphate, a black precipitate of copper sulphate is obtained and the sulphuric acid so formed remains in the solution. The reaction is an example of :-
(a)A combination reaction
(b)A displacement reaction
(c)A decomposition reaction
(d)A double decomposition reaction
Question 313
What happens when copper rod is dipped in iron sulphate solution :-
(a)Copper displaces iron
(b)Blue color of copper sulphate solution is obtained
(c)No reaction takes place
(d)Reaction is exothermic
Question 314
A student added dilute HCI to a test tube containing zinc granules and made following observations :-
(a)The zinc surface became dull and black
(b)A gas evolved which burnt with a pop sound
(c)The solution remained colorless
(d)The solution becomes green in color.
Question 315
A dilute solution of sodium carbonate was added to two test tubes one containing dilute HCI (A) and the other containing dilute NaOH (B). the correct observation was :-
(a)A brown colored gas liberated in test tube A
(b)A brown colored gas liberated in test tube B
(c)A colorless gas liberated in test tube A
(d)A colorless gas liberated in test tube B
Question 316
A balanced chemical equation is in accordance with
(a)Avogadro’s law
(b)Law of multiple proportion
(c)Law of conservation of mass
(d)Law of gaseous volumes
Question 317
The equation
Cu + xHNO3 -> Cu(NO3)2 + yNO2 + 2H2O
The values of x and y are
(a)3 and 5
(b)8 and 6
(c)4 and 2
(d)7 and 1
Question 318
Zn + H2SO4(dil) ->ZnSO4 + H2
Above reaction is
(a)Decomposition reaction
(b)Single displacement reaction
(c)Combination reaction
(d)Synthesis reaction
Question 319.
The reaction in which two compounds exchange their ions to form two new compounds is
(a)A displacement reaction
(b)A decomposition reaction
(c)An isomerization reaction
(d)A double displacement reaction
Question 320
When the gases sulphur dioxide and hydrogen sulphide mix in the presence of water, the reaction is
SO2 + 2H2S -> 2H2O + 3S. here hydrogen sulphide is acting as
(a)An oxidizing agent
(b)A reducing agent
(c)A dehydrating agent
(d)A catalyst
Question 321
CuO + H2 ->H2O + Cu, reaction is an example of
(a)Redox reaction
(b)Synthesis reaction
(c)Neutralization
(d)Analysis reaction
Question 322
A substance which oxidized itself and reduces other is known as
(a)Oxidizing agent
(b)Reducing agent
(c)Both of these
(d)None of these
Question 323
A redox reaction is one in which
(a)Both the substance are reduced
(b)Both the substance are oxidized
(c)An acid is neutralized by the base
(d)One substance is oxidized while the other is reduced
Question 324
In the following equation:
Na2CO3 + xHCI -> 2NaCI +CO2 + H2O, the value of x is
(a)1
(b)2
(c)3
(d)4
Question 325
In the equation, NaOH + HNO3 -> NaNO3 + H2O nitric acid is acting as
(a)An oxidizing agent
(b)An acid
(c)A nitrating agent
(d)A dehydrating agent
Question 326
Fe2O3+ 2AI2O3 + 2Fe
The above reaction is an example of a
(a)Combination reaction
(b)Double displacement reaction
(c)Decomposition reaction
(d)Displacement reaction
Question 327
White silver chloride in sunlight turns to
(a)Grey
(b)Yellow
(c)Remain white
(d)Red
Question 328
Black and white photography uses
(a)Decomposition of silver chloride
(b)Decomposition of silver bromide
(c)Both
(d)None of these
Question 329
When copper powder is heated it gets coated with
(a)Black copper oxide
(b)Yellow copper oxide
(c)Red copper oxide
(d)None of these
Question 330
Combination of phosphorus and oxygen is an example of
(a)Oxidation
(b)Reduction
(c)Rancidity
(d)None of these
Question 331
Rusting of an iron is an example of
a)Reduction
b)Ionization
c)Oxidation
d)Dissociation
Question 322
Which of the following does not corrode when exposed to the atmosphere-
(a)Iron
(b)Copper
(c)Gold
(d)Silver
Question 323.
Take about 1.0g CaCO3 in a test tube. Heat it over a flame, when a colorless gas comes out. The reaction is called a
(a)Decomposition reaction
(b)Displacement reaction
(c)Double decomposition reaction
(d)Double displacement reaction
Question 324.
Hydrogen sulphide (H2S) is a strong reducing agent. Which of the following reactions shows its reducing action
(a)Cd(NO3)2 + H2S -> CdS + 2HNO3
(b)CuSO4 + H2S -> CuS + H2SO4
(c)2FeCl3 + H2S -> 2FeCl2 + 2HCI + S
(d)Pb(NO3)2 +H2S -> PbS + 2CH3COOH
Question 325.
When P reacts with caustic soda, the products are PH3 and NaH2PO2. This reaction is an example of
(a)Oxidation
(b)Reduction
(c)Oxidation and reduction (redox)
(d)Neutralization
Question 326.
2CuI-> Cu + CuI2, the reaction is
(a)Redox
(b)Neutralization
(c)Oxidation
(d)Reduction
Question 327.
When copper turning are added to silver nitrate solution, a blue coloured solution is formed after some time. It is because, copper
(a)Displaces silver from the solution
(b)Forms a blue colored complex with AgNO3
(c)Is oxidized to Cu2+Cu2+
(d)Is reduced to Cu2+Cu2+
Question 328.
Zn2+ (aq) +2e -> Zn(s). this is
(a)Oxidation
(b)Reduction
(c)Redox reaction
(d)None of these
Q329. Assertion (A) : Decomposition of vegetable matter into compost is an example of exothermic reactions.
Reason (R) : Exothermic reaction are those reactions in which heat is evolved.
330. Assertion (A) : When HCl is added to zinc granules, a chemical reaction occurs.
Reason (R) : Evolution of a gas and change in colour indicate that the chemical reaction is taking place.
341. Assertion (A) : Calcium carbonate when heated gives calcium oxide and water.
Reason (R) : On heating calcium carbonate, decomposition reaction takes place.
342. Assertion (A) : Brown fumes are produced when lead nitrate is heated.
Reason (R) : Nitrogen dioxide gas is produced as a by product due to the decomposition of lead nitrate.
343. Assertion (A) : White silver chloride turns grey in sunlight.
Reason (R) : Decomposition of silver chloride in presence of sunlight takes place to form silver metal and chlorine gas.
344. Assertion (A): Pungent smelling gas is produced when sulphur burns in air.
Reason (R) : Sulphur trioxide is formed on reaction of sulphur with oxygen.
345. Assertion (A) : In a reaction of copper with oxygen, copper serves as a reducing agent.
Reason (R) : The substance which gains oxygen in a chemical reaction acts as a reducing agent.
346 Assertion (A) : In electrolysis of water, the volume of hydrogen liberated is twice the volume of oxygen formed.
Reason (R) : Water (H,0) has hydrogen and oxygen in the ratio of 1:2 by volume.
347. Assertion (A): Corrosion of iron is commonly known as rusting.
Reason (R) : Corrosion of iron occurs in presence of water and air.
348 Assertion (A) : The balancing of chemical equations is based on law of conservation of mass.
Reason (R) : Total mass of reactants is equal to total mass of products.
349.. Assertion (A): In a balanced chemical equation, total mass of the reactants is equal to the total mass of the products.
Reason (R): Mass can neither be created nor destroyed during a chemical change.
350.. Assertion (A): Iron articles are painted so as to prevent them from rusting.
Reason (R): When the surface of iron is coated with paint, its surface does not come in contact with oxygen and moisture therefore rusting does not take place.
351 . Assertion (A) : Chemical reaction changes the physical and chemical state of a substance.
Reason (R) : When electric current is passed through water (liquid), it decomposes to produce hydrogen and
oxygen gases.
352. Assertion (A): When calcium carbonate is heated, it decomposes to give calcium oxide and carbon dioxide.
Reason (R): The decomposition reaction takes place on application of heat, therefore, it is an endothermic reaction.
353 Assertion (A): Zinc reacts with sulphuric acid to form zinc sulphate and hydrogen gas and it is a displacement reaction.
Reason (R): Zinc reacts with oxygen to form zinc oxide
354. Assertion (A): Chips manufacturers usually Ilush bags of chips with gas such as nitrogen to prevent the chips from getting oxidised.
Reason (R): This increase the taste ot the chips and helps in their digestion.
355. Assertion (A): Exposure of silver chloride to sunlight for a long duration turns grey due to the formation of silver by decomposition of silver chloride.
Reason (R): In this process, sublimation of silver chloride takes place.
356. Assertion (A): Rusting of iron metal is the most common form of corrosion.
Reason (R): The effect of rusting of iron can be reversed if they are left open in sunlight.
357. Assertion (A): AgBr is used on photographic and X-ray film.
Reason (R): AgBr is photosensitive and changes to Ag and bromine in presence of sunlight and undergoes
decomposition reaction.
358. Assertion (A): Magnesium ribbon keeps on burning in atmosphere of nitrogen.
Reason (R) : Magnesium reacts with nitrogen to form magnesium nitride and this reaction is combination reaction.
359.. Assertion (A): A lead nitrate on thermal decomposition gives lead oxide, brown coloured nitrogen dioxide and oxygen gas.
Reason (R): Lead nitrate reacts with potassium iodide to form yellow ppt. of lead iodide and the reaction is double displacement as well as precipitation reaction.
CASE STUDY
Those reactions in which two compounds react by an exchange of ions to form two new compounds are called double displacement reactions. A double displacement reaction usually occurs in solution and one of the products, being insoluble, precipitate out (separates as a solid). Any reaction in which an insoluble solid (called precipitate) is formed that separates from the solution is called a precipitation reaction. The reaction in which acid or acidic oxide reacts with base or basic oxide to form salt and water is called neutralisation reaction.
For example,
2NaOH + H2SO4⟶Na2SO4 + H2O
360.When hydrogen sulphide gas is passed through a blue solution of copper sulphate, a black precipitate of copper sulphide is obtained and the sulphuric acid so formed remains in the solution. The reaction is an example of a
(a) combination reaction
(b) displacement reaction
(c) decomposition reaction
d) double displacement reaction
(361i) Which of the following is not a double displacement reaction?
(a) AgNO3(aq)+NaCl(aq)⟶AgCl(s)+NaNO3(aq)
(b) Zn(s)+H2SO4(aq)⟶ZnSO4(aq)+H2(g)
362. Barium chloride on reaction with ammonium sulphate forms barium sulphate and ammonium chloride. Which of the following correctly represents the type of the reaction involved?
(I) Displacement reaction
(II) Precipitation reaction
(III) Combination reaction
(IV) Double displacement reaction
(a) (I) only
(b) (II) only
(c) (III) and (IV) only
(d) (II) and ( V) onlly
363. Identify A in the following reaction.
AlCl3(aq)+3NH4OH(aq)⟶A+3NH4Cl(aq)AlCl3(aq)+3NH4OH(aq)⟶A+3NH4Cl(aq)
(a) AI(OH)3(b) Al2 O3(c) AIH3(d) AIN
(a) AI(OH)3(b) Al2 O3(c) AIH3(d) AIN
364. Consider the following reaction,
BaCl2+Na2SO4⟶BaSO4+2NaCl
identify the precipitate in the reaction,
(a) BaCl2(b) BaSO4(c) Na2sO4
Case study
• The earlier concept of oxidation and reduction is based on the addition or removal of oxygen or hydrogen elements so, in terms of oxygen and hydrogen, oxidation is addition of oxygen to a substance and removal of hydrogen from a substance. On the other hand, reduction is addition of hydrogen to a substance and removal of oxygen from a substance. The substance which gives oxygen to another substance or removes hydrogen from another substance in an oxidation reaction is known as oxidising agent, while the substance which gives hydrogen to another substance or removes oxygen from another substance in a reduction reaction is known as reducing agent. For example,
(365 A redox reaction is one in which
(a) both the substances are reduced(b) both the substances are oxidised(c) an acid is neutralised by the base(d) one substance is oxidised while the other is reduced.
(366 In the reaction, H2 S+Cl2⟶S+2HClH2 S+Cl2⟶S+2HCl
(a) H2S is the reducing agent.(b) HCI is the oxidising agent.(c) H2S is the oxidising agent.(d) Cl2 is the reducing agent.
(367 Which ofthe following processes does not involve either oxidation or reduction?
(a) Formation of slaked lime from quick lime.(b) Heating mercuric oxide.(c) Formation of manganese chloride from manganese oxide (MnO2).(d) Formation of zinc from zinc blende.
(368 Mg+CuO⟶MgO+Cu (iv) Mg+CuO⟶MgO+Cu
Which of the following is wrong relating to the above reaction?
(a) CuO gets reduced(b) Mg gets oxidised. (c) CuO gets oxidised.(d) It is a redox reaction.
(369.Identify the correct oxidising agent and reducing agent in the following reaction.
Fe2O3+2Al⟶2Fe+Al2O3Fe2O3+2Al⟶2Fe+Al2O3
(a) AI- Oxidising agent, Fe2O3 - Reducing agent(
b) Fe2 O3 - Oxidising agent, AI- Reducing agent(
c) Fe - Oxidising agent, Al2O3 - Reducing agent
(d) Fe2O3 - Oxidising agent, Al2O3 - Reducing agent4
Oxidation has damaging effect on metals as well as on food. The damaging effect of oxidation on metal is studied as corrosion and that on food is studied as rancidity. The phenomenon due to which metals are slowly eaten away by the reaction of air, water and chemicals present in atmosphere, is called corrosion. For example, iron articles are shiny when new, but get coated with a reddish brown powder when left for sometime. This process is known as rusting of iron. Rancidity is the process of slow oxidation of oil and fat (which are volatile in nature) present in the food materials resulting in the change of smell and taste in them.
(370 Rancidity can be prevented by
(a) adding antioxidants(b) packaging oily food in nitrogen gas(c) both (a) and (b)(d) none of these.
(37i) Combination of phosphorus and oxygen is an example of
(a) oxidation(b) reduction(c) rancidity(d) none of these
(372) A science teacher wrote the following statements about rancidity :
(I) When fats and oils are reduced, they become rancid.
(II) In chips packet, rancidity is prevented by oxygen.
(III) Rancidity is prevented by adding antioxidants.
Select the correct option.
a) (I) only(b) (II) and (III) only(c) (III) only(d) (I), (II), and (III)
373() Two statements are given below regarding rusting of iron.
(I) The rusting of iron is a redox reaction and reaction occurs as, 4Fe+3O2⟶4Fe3++6O2−4Fe+3O2⟶4Fe3++6O2−
(II) The metallic iron is oxidised to Fe2+ and O2 is reduced to O2−Fe2+ and O2 is reduced to O2−
Select the correct statement(s).
(a) I only(b) II only(c) Both I and II(d) None of these
(374 Which of the following measures can be adopted to prevent or slow down rancidity?
(I) Food materials should be packed in air tight container.
(II) Food should be refrigerated.
(III) Food materials and cooked food should be kept away from direct sunlight
(a) Only II and III(b) Only I and III(c)
•
Answer
1. b) Except (b) all other reactions involve compounds.
2. (d) CuSO4 +H2S -> CuS + H2SO4
It is a Double decomposition
3.(c) Iron is more reactive than copper, hence Cu will not displace iron from iron sulphate, hence no reaction will take place.
4.(b) Zn + 2HCl -> ZnCl2 + H2
5.(c) Na2CO3+ 2HCI -> 2NaCI + H2O + CO2
6.(c)
7.(c) Cu +4HNO3 -> Cu(NO3)2 + 2NO2 + 2H2O
8.(b)
9.(d)
10.(b) Here H2S is oxidizing in to H2O, hence behave as a reducing agent.
11.(a)
12.(b)
13.(d)
14. (b) Na2CO3 + 2HCI ->2NaCI + CO2 + H2O
15.(b) The reaction represents a neutralization reaction in which base (NaOH) reacts with an acid (HNO3) to form salt (NaNO3) and water (H2O).
16.(d)
17.(a) Write silver chloride in sunlight turns to grey.
18.(b)
19.(a) 2Cu + O2 -> 2CuO
Black
20.(a) 4P + 3O2 ->2P2O3
(Oxidation)
Or 4P + 5O2 ___ 2P2O5
(Oxidation)
21.(c) During rusting iron get oxidized to form rust (Fe2O3 x H2O)
22.(c) Gold is very least reactive hence does not corrode at all.
23.(a)
24.(c)
N the given reaction H2 is undergoing oxidation, hence behave as reducing agent.
25.(c)
It shows oxidation and reduction (redox) properties.
26.(a) Oxidation and reduction both occur so the reaction is redox.
27.(c) Cu is above of Ag in electrochemical series and thus
Cu + 2Ag+-> Cu2+ + 2Ag reaction occurs.
28.(b) reduction.
29.a
30.b
31.d
32.a
33.a
34.c
35.a
36.c
37.b
39.a
40.a
41a
42b
43b
44b
45c
46c
47c
48a
49a
50b
Oxidation has damaging effect on metals as well as on food. The damaging effect of oxidation on metal is studied as corrosion and that on food is studied as rancidity. The phenomenon due to which metals are slowly eaten away by the reaction of air, water and chemicals present in atmosphere, is called corrosion. For example, iron articles are shiny when new, but get coated with a reddish brown powder when left for sometime. This process is known as rusting of iron. Rancidity is the process of slow oxidation of oil and fat (which are volatile in nature) present in the food materials resulting in the change of smell and taste in them.
(370 Rancidity can be prevented by
(a) adding antioxidants(b) packaging oily food in nitrogen gas(c) both (a) and (b)(d) none of these.
(37i) Combination of phosphorus and oxygen is an example of
(a) oxidation(b) reduction(c) rancidity(d) none of these
(372) A science teacher wrote the following statements about rancidity :
(I) When fats and oils are reduced, they become rancid.
(II) In chips packet, rancidity is prevented by oxygen.
(III) Rancidity is prevented by adding antioxidants.
Select the correct option.
a) (I) only(b) (II) and (III) only(c) (III) only(d) (I), (II), and (III)
373() Two statements are given below regarding rusting of iron.
(I) The rusting of iron is a redox reaction and reaction occurs as, 4Fe+3O2⟶4Fe3++6O2−4Fe+3O2⟶4Fe3++6O2−
(II) The metallic iron is oxidised to Fe2+ and O2 is reduced to O2−Fe2+ and O2 is reduced to O2−
Select the correct statement(s).
(a) I only(b) II only(c) Both I and II(d) None of these
(374 Which of the following measures can be adopted to prevent or slow down rancidity?
(I) Food materials should be packed in air tight container.
(II) Food should be refrigerated.
(III) Food materials and cooked food should be kept away from direct sunlight
(a) Only II and III(b) Only I and III(c)
•
Answer
1. b) Except (b) all other reactions involve compounds.
2. (d) CuSO4 +H2S -> CuS + H2SO4
It is a Double decomposition
3.(c) Iron is more reactive than copper, hence Cu will not displace iron from iron sulphate, hence no reaction will take place.
4.(b) Zn + 2HCl -> ZnCl2 + H2
5.(c) Na2CO3+ 2HCI -> 2NaCI + H2O + CO2
6.(c)
7.(c) Cu +4HNO3 -> Cu(NO3)2 + 2NO2 + 2H2O
8.(b)
9.(d)
10.(b) Here H2S is oxidizing in to H2O, hence behave as a reducing agent.
11.(a)
12.(b)
13.(d)
14. (b) Na2CO3 + 2HCI ->2NaCI + CO2 + H2O
15.(b) The reaction represents a neutralization reaction in which base (NaOH) reacts with an acid (HNO3) to form salt (NaNO3) and water (H2O).
16.(d)
17.(a) Write silver chloride in sunlight turns to grey.
18.(b)
19.(a) 2Cu + O2 -> 2CuO
Black
20.(a) 4P + 3O2 ->2P2O3
(Oxidation)
Or 4P + 5O2 ___ 2P2O5
(Oxidation)
21.(c) During rusting iron get oxidized to form rust (Fe2O3 x H2O)
22.(c) Gold is very least reactive hence does not corrode at all.
23.(a)
24.(c)
N the given reaction H2 is undergoing oxidation, hence behave as reducing agent.
25.(c)
It shows oxidation and reduction (redox) properties.
26.(a) Oxidation and reduction both occur so the reaction is redox.
27.(c) Cu is above of Ag in electrochemical series and thus
Cu + 2Ag+-> Cu2+ + 2Ag reaction occurs.
28.(b) reduction.
29.a
30.b
31.d
32.a
33.a
34.c
35.a
36.c
37.b
39.a
40.a
41a
42b
43b
44b
45c
46c
47c
48a
49a
50b
Thanks a lot!Very helpful!
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