1. Which of the following is a displacement reaction?
Answer/ Explanation
Answer: b
Explaination: Reason: Here sodium (Na) displaces to form sodium hydroxide.
Explaination: Reason: Here sodium (Na) displaces to form sodium hydroxide.
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
(a) basic magnesium carbonate
(b) basic magnesium oxide
(c) basic magnesium sulphide
(d) basic magnesium chloride
Answer
Answer: a
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)
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)
Answer
Answer: c
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)
(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)
Answer/ Explanation
Answer: a
Explaination: Reason: In both the cases, heat energy is evolved.
Explaination: Reason: In both the cases, heat energy is evolved.
5. Oxidation is a process which involves
(a) addition of oxygen
(b) addition of hydrogen
(c) removal of oxygen
(d) removal of hydrogen
(a) addition of oxygen
(b) addition of hydrogen
(c) removal of oxygen
(d) removal of hydrogen
Answer
6. The process of reduction involves
(a) addition of oxygen
(b) addition of hydrogen
(c) removal of oxygen
(d) removal of hydrogen
(a) addition of oxygen
(b) addition of hydrogen
(c) removal of oxygen
(d) removal of hydrogen
Answer
7. Three beakers labelled as A, B and C each containing 25 ml of water were taken. A small amount of NaOH, anhydrous CuSO4and 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)
(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)
Answer
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
(a) 1:2
(b) 1:1
(c) 2:1
(d) 1:8
Answer
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
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
Answer
10. MnO2 + 4HCl → 2 + 2H2O + Cl2
Identify the substance oxidized in the above . equation.
(a) MnCl2
(b) HCl
(c) H2O
(d) MnO2
Identify the substance oxidized in the above . equation.
(a) MnCl2
(b) HCl
(c) H2O
(d) MnO2
Answer/ Explanation
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
(a) CaOCl2
(b) Ca (OH)2
(c) CaO
(d) CaCO3
Answer/ Explanation
12. When Ag is exposed to air it gets a black coating of
(a) AgNO3
(b) Ag2S
(c) Ag2O
(d) Ag2CO3
(a) AgNO3
(b) Ag2S
(c) Ag2O
(d) Ag2CO3
Answer
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
(a) Dilution of sulphuric acid
(b) Sublimation of dry ice
(c) Condensation of water vapours
(d) Respiration in human beings
Answer
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
(a) Lead sulphate (insoluble)
(&) Lead acetate
(c) Ammonium nitrate
(d) Potassium sulphate
Answer
15. What type of chemical reactions take place when electricity is passed through water?
(a) Displacement
(b) Combination
(c) Decomposition
(d) Double displacement
(a) Displacement
(b) Combination
(c) Decomposition
(d) Double displacement
Answer/ Explanation
16. Select the oxidising agent for the following reaction:
H2S + I2 > 2HI + S
(a) I2
(b) H2S
(C) HI
(d) S
H2S + I2 > 2HI + S
(a) I2
(b) H2S
(C) HI
(d) S
Answer
17. A substance added to food containing fats and oils is called:
(a) Oxidant
(b) Rancid
(c) Coolant
(d) Antioxidant
(a) Oxidant
(b) Rancid
(c) Coolant
(d) Antioxidant
Answer
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
(a) antioxidation
(b) reduction
(c) rancidity
(d) corrosion
Answer
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
(a) 1 : 1
(b) 2:1
(c) 4:1
(d) 1:2
Answer
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
(a) SO2 + 2H2S → 2H20 + 3S
(b) SO2 + 2H2S → H20 + 3S
(c)SO2 + H2S → H2O + S
(d) SO2 + H2O → SO3 + H2
Answer
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
(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
Answer/ Explanation
22. Pb + CuCl2 → PbCl2 + Cu
The above reaction is an example of:
(a) combination
(b) double displacement
(c) decomposition
(d) displacement
The above reaction is an example of:
(a) combination
(b) double displacement
(c) decomposition
(d) displacement
Answer
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
(b) Nitrogen or Oxygen
(c) Carbon dioxide or Helium
(d) Helium or Nitrogen
Answer
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.
(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.
Answer
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)
(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)
Answer
26. When green coloured ferrous sulphate crystals are heated, the colour of the crystal changes because
(a) it is decomposed to ferric oxide
(b) it loses water of crystallisation
(c) it forms SO2
(d) it forms SO3
(a) it is decomposed to ferric oxide
(b) it loses water of crystallisation
(c) it forms SO2
(d) it forms SO3
Answer
27. 2HNO3 + Ca(OH)2 → Ca(NO3)2 + 2H2O; is an example of
(i) displacement reaction
(ii) double displacement reaction
(iii) neutralisation reaction
(iv) combination reaction.
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iv)
(i) displacement reaction
(ii) double displacement reaction
(iii) neutralisation reaction
(iv) combination reaction.
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iv)
Answer
28. Burning Magnesium ribbon is brought in the gas jar of carbon dioxide. Which of the following is correct ?
(i) It keeps on burning
(ii) It gets extinguished
(iii) Although CO2 is non-supporter of combustion but burning magnesium breaks CO2 into carbon and oxygen, oxygen helps in burning.
(iv) Carbon dioxide is supporter of combustion.
(a) (i) and (iv)
(b) (i) and (iii)
(c) (i) and (ii)
(d) (iii) and (iv)
(i) It keeps on burning
(ii) It gets extinguished
(iii) Although CO2 is non-supporter of combustion but burning magnesium breaks CO2 into carbon and oxygen, oxygen helps in burning.
(iv) Carbon dioxide is supporter of combustion.
(a) (i) and (iv)
(b) (i) and (iii)
(c) (i) and (ii)
(d) (iii) and (iv)
Answer
29. What is observed when a solution of potassium iodide is added to silver nitrate solution ?
(a) No reaction takes place
(b) White precipitate of silver iodide is formed
(c) yellow precipitate of Agl is formed
(d) Agl is soluble in water.
(a) No reaction takes place
(b) White precipitate of silver iodide is formed
(c) yellow precipitate of Agl is formed
(d) Agl is soluble in water.
Answer
30. Identify ‘x’, ‘y’ and ‘z’ in the following balanced reaction
(a) 2, 4, 2
(b) 2, 2, 4
(c) 2, 4, 4
(d) 4, 2, 2
(a) 2, 4, 2
(b) 2, 2, 4
(c) 2, 4, 4
(d) 4, 2, 2
Answer
31. Which of the following is precipitation as well as double displacement reaction?
Answer
32. Which of the following reactions will not take place ?
(a) Zn + CuSO4 → ZnSO3 + Cu
(b) 2KBr + Cl2 → KCl + Br2
(c) Zn + MgSO4 → ZnSO4 + Mg
(d) Mg + FeSO4 → MgSO4 + Fe
(a) Zn + CuSO4 → ZnSO3 + Cu
(b) 2KBr + Cl2 → KCl + Br2
(c) Zn + MgSO4 → ZnSO4 + Mg
(d) Mg + FeSO4 → MgSO4 + Fe
Answer
33. Which of the following involves combination of two elements ?
(a) N2(g) + 3H2(g) → 2NH3(g)
(b) CaO(s) + CO2(g) → CaCO3(g)
(c) 2SO2(g) + O2(g) → 2SO3f(g)
(d) NH3(g) + HCl(g) → NH4Cl(s)
(a) N2(g) + 3H2(g) → 2NH3(g)
(b) CaO(s) + CO2(g) → CaCO3(g)
(c) 2SO2(g) + O2(g) → 2SO3f(g)
(d) NH3(g) + HCl(g) → NH4Cl(s)
Answer
34. In the reaction Hg2Cl2 + Cl2 → 2HgCl2The reducing agent is
(a) Hg2Cl2
(b) Cl2
(c) HgCl2
(d) Both Cl2 and HgCl2
(a) Hg2Cl2
(b) Cl2
(c) HgCl2
(d) Both Cl2 and HgCl2
Answer
35. Oxidation involves
(i) gain of electron
(ii) loss of electron
(iii) addition of oxygen or electronegative element
(iv) removal ofhydrogenorelectropositive element
(a) (i), (ii), (iii)
(b) (ii), (iii), (iv)
(c) (i), (iii), (iv)
(d) (i), (ii), (iv)
(i) gain of electron
(ii) loss of electron
(iii) addition of oxygen or electronegative element
(iv) removal ofhydrogenorelectropositive element
(a) (i), (ii), (iii)
(b) (ii), (iii), (iv)
(c) (i), (iii), (iv)
(d) (i), (ii), (iv)
Answer
36. The formula of Ammonium phosphate is
(a) NH4PO4
(b) (NH4)2PO4
(c) (NH4)3PO4
(d) (NH4)3(PO4)2
(a) NH4PO4
(b) (NH4)2PO4
(c) (NH4)3PO4
(d) (NH4)3(PO4)2
Answer
37. Which of the following is a thermal decomposition reaction ?
(a) 2H2O → 2H2 + O2
(b) 2AgCl → 2Ag + Cl2
(c) ZnCO3 → ZnO + CO2
(d) H2(g) + Cl2(g) → 2HCl(g)
(a) 2H2O → 2H2 + O2
(b) 2AgCl → 2Ag + Cl2
(c) ZnCO3 → ZnO + CO2
(d) H2(g) + Cl2(g) → 2HCl(g)
Answer
38. The following reaction is an example of a
4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g)
(i) displacement reaction
(ii) combination reaction
(iii) redox reaction
(iv) neutralisation reaction [NCERT Exemplar Problems]
(a) (i) and (iv)
(b) (ii) and (iii)
(c) (i) and (iii)
(d) (iii) and (iv)
4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g)
(i) displacement reaction
(ii) combination reaction
(iii) redox reaction
(iv) neutralisation reaction [NCERT Exemplar Problems]
(a) (i) and (iv)
(b) (ii) and (iii)
(c) (i) and (iii)
(d) (iii) and (iv)
Answer
39. Which of the following statements about the given reaction are correct ?
3Fe(s) + 4H2O(g) → Fe3O4(g) + 6H2(g)
(i) Iron metal is getting oxidised
(ii) Water is getting reduced
(iii) Water is acting as reducing agent
(iv) Water is acting as an oxidising agent [NCERT Exemplar Problems]
(a) (i), (ii) and (iii)
(b) (iii) and (iv)
(c) (i), (ii) and (iv)
(d) (ii) and (iv)
3Fe(s) + 4H2O(g) → Fe3O4(g) + 6H2(g)
(i) Iron metal is getting oxidised
(ii) Water is getting reduced
(iii) Water is acting as reducing agent
(iv) Water is acting as an oxidising agent [NCERT Exemplar Problems]
(a) (i), (ii) and (iii)
(b) (iii) and (iv)
(c) (i), (ii) and (iv)
(d) (ii) and (iv)
Answer
40. 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) [NCERT Exemplar Problems]
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (i) and (iv)
(d) (iii) and (iv)
(i) Reaction of water with quick lime
(ii) Dilution of an acid
(iii) Evaporation of water
(iv) Sublimation of camphor (crystals) [NCERT Exemplar Problems]
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (i) and (iv)
(d) (iii) and (iv)
Answer
41. Which among the following is (are) double displacement reactions ? [NCERT Exemplar Problems]
(i) Pb + CuCl2 → PbCl2 + Cu
(ii) Na2SO4 + BaCl2 → BaSO4 + 2NaCl
(iii) C + O2 → CO2
(iv) CH4 + 2O2 → CO2 + 2H2O
(a) (i) and (iv)
(b) (ii) only
(c) (i) and (ii)
(d) (iii) and (iv)
(i) Pb + CuCl2 → PbCl2 + Cu
(ii) Na2SO4 + BaCl2 → BaSO4 + 2NaCl
(iii) C + O2 → CO2
(iv) CH4 + 2O2 → CO2 + 2H2O
(a) (i) and (iv)
(b) (ii) only
(c) (i) and (ii)
(d) (iii) and (iv)
Answer
42. 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 ? [NCERT Exemplar Problems]
(i) Displacement reaction
(ii) Precipitation reaction
(iii) Combination reaction
(iv) Double displacement reaction
(a) (i) only
(b) (ii) only
(c) (iv) only
(d) (ii) and (iv)
(i) Displacement reaction
(ii) Precipitation reaction
(iii) Combination reaction
(iv) Double displacement reaction
(a) (i) only
(b) (ii) only
(c) (iv) only
(d) (ii) and (iv)
Answer
43. Electrolysis of water is a decomposition reaction. The molar ratio of hydrogen and oxygen gases liberated during electrolysis of water is [NCERT Exemplar Problems]
(a) 1 : 1
(b) 2 : 1
(c) 4 : 1
(d) 1 : 2
(a) 1 : 1
(b) 2 : 1
(c) 4 : 1
(d) 1 : 2
Answer
44. Which of the following is (are) an endothermic process(es) ? [NCERT Exemplar Problems]
(z) Dilution of sulphuric acid
(ii) Sublimation of dry ice
(iii) Condensation of water vapours
(iv) Evaporation of water
(a) (i) and (iii)
(b) (ii) only
(c) (iii) only
(d) (ii) and (iv)
(z) Dilution of sulphuric acid
(ii) Sublimation of dry ice
(iii) Condensation of water vapours
(iv) Evaporation of water
(a) (i) and (iii)
(b) (ii) only
(c) (iii) only
(d) (ii) and (iv)
Answer
45. Which of the following gases can be used for storage of fresh sample of an oil for a long time? [NCERT Exemplar Problems]
(a) Carbon dioxide or oxygen
(b) Nitrogen or oxygen
(c) Carbon dioxide or helium
(d) Helium or nitrogen
(a) Carbon dioxide or oxygen
(b) Nitrogen or oxygen
(c) Carbon dioxide or helium
(d) Helium or nitrogen
Answer
46. The following reaction is used for the preparation of oxygen gas in the laboratory
Which of the following statement(s) is (are) correct about the reaction ? [NCERT Exemplar Problems]
(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 release of heat
(d) It is a photochemical decomposition reaction and exothermic in nature
Which of the following statement(s) is (are) correct about the reaction ? [NCERT Exemplar Problems]
(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 release of heat
(d) It is a photochemical decomposition reaction and exothermic in nature
Answer
47. Which one of the following processes involve chemical reactions ? [NCERT Exemplar Problems]
(a) Storing of oxygen gas under pressure in a gas cylinder
(b) Liquefaction of air
(c) Keeping petrol in a china dish in the open
(d) Heating copper wire in presence of air at high temperature
(a) Storing of oxygen gas under pressure in a gas cylinder
(b) Liquefaction of air
(c) Keeping petrol in a china dish in the open
(d) Heating copper wire in presence of air at high temperature
Answer
48. In which of the following chemical equations, the abbreviations represent the correct states of the reactants and products involved at reaction temperature ? [NCERT Exemplar Problems]
(a) H2(l) + O2(l) → 2H2O(g)
(b) H2(g) + O2(l) → 2H2O(l)
(c) H2(g) + O2(g) → 2H2O(l)
(d) H2(g) + O2(g) → m2O(g)
(a) H2(l) + O2(l) → 2H2O(g)
(b) H2(g) + O2(l) → 2H2O(l)
(c) H2(g) + O2(g) → 2H2O(l)
(d) H2(g) + O2(g) → m2O(g)
Answer
49. The brown gas evolved on heating of copper nitrate is
(a) O2
(b) NO2
(c) N2
(d) NO
(a) O2
(b) NO2
(c) N2
(d) NO
Answer/Explanation
50. Zinc reacts with silver nitrate to form which compounds?
(a) Zn(NO3)2 + Ag
(b) ZnNO3 + Ag
(c) AgNO3 + Zn(NO3)2
(d) Ag + Zn(NO3)3
(a) Zn(NO3)2 + Ag
(b) ZnNO3 + Ag
(c) AgNO3 + Zn(NO3)2
(d) Ag + Zn(NO3)3
Answer/Explanation
51. MnO2 + 4HCl → MnCl2 + H2O + Cl2 The oxidising agent is
(a) MnO2
(b) HCl
(c) MnCl2
(d) Ag + Zn(NO3)3
(a) MnO2
(b) HCl
(c) MnCl2
(d) Ag + Zn(NO3)3
Answer/Explanation
52.
The colour of iodine is
(a) green
(b) purple
(c) brown
(d) pink
The colour of iodine is
(a) green
(b) purple
(c) brown
(d) pink
Answer/Explanation
Direction (Q53 to Q57): In the following Questions, the Assertion and Reason have been put forward. Read the statements carefully and choose the correct alternative from the following:
(a) Both the Assertion and the Reason are correct and the Reason is the correct explanation of the Assertion.
(b) The Assertion and the Reason are correct but the Reason is not the correct explanation of the Assertion.
(c) Assertion is true but the Reason is false.
(d) The statement of the Assertion is false but the Reason is true.
53. Assertion: AgBr is used on photographic and x-ray film.
Reason: AgBr is photosensitive and changes to Ag and bromine in presence of sunlight and undergoes decomposition reaction.
(a) Both the Assertion and the Reason are correct and the Reason is the correct explanation of the Assertion.
(b) The Assertion and the Reason are correct but the Reason is not the correct explanation of the Assertion.
(c) Assertion is true but the Reason is false.
(d) The statement of the Assertion is false but the Reason is true.
53. Assertion: AgBr is used on photographic and x-ray film.
Reason: AgBr is photosensitive and changes to Ag and bromine in presence of sunlight and undergoes decomposition reaction.
Answer/Explanation
54. Assertion: Magnesium ribbon keeps on burning in atmosphere of nitrogen. Reason: Magnesium reacts with nitrogen to form magnesium nitrides and this reaction is combination reaction.
Answer/Explanation
55. Assertion: Zinc reacts with sulphuric acid to form zinc sulphate and hydrogen gas and it is displacement reaction.
Reason: Zinc reacts with oxygen to form zinc oxide.
Reason: Zinc reacts with oxygen to form zinc oxide.
Answer/Explanation
56. Assertion: MnO2 + 4HCl → MnCl2 + Cl2+ 2H2O is redox reaction.
Reason: MnO2 oxides HCl to Cl2 and gets reduced to MnCl2.
Reason: MnO2 oxides HCl to Cl2 and gets reduced to MnCl2.
Answer/Explanation
57. 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.
Answer/Explanation
58. The colour of FeSO4 crystal before ___________ heating is and after heating is ___________ .
Answer/Explanation
59. SO2 + 2H2S → 2H2O + 3S; SO2 is ___________ acting as agent.
Answer/Explanation
60. The reaction Cu + xHNO3 (cone.) → Cu(NO3)2 + yNO2 + zH2O The values of x, y and z are ___________ , ___________ and ___________ .
Answer/Explanation
61. A balanced chemical equation has equal masses of various elements in ___________ and ___________ .
Answer/Explanation
62.
is an example of ___________ reaction.
is an example of ___________ reaction.
Answer/Explanation
63. All combustion reactions are oxidation reactions. [True/False]
Answer/Explanation
64. Displacement reaction can be redox reaction also. [True/False]
Answer/Explanation
65. In H2S + Cl2 → 2HCl + S, Cl2 is oxidising agent and H2S is reducing agent. [True/False]
Answer/Explanation
66. CaO + 2HCl → CaCl2 + H2O is neutralisation reaction. [True/False]
Answer/Explanation
67. Chemical reactions are those processes where new substances with old properties are formed. [True/False]
Answer/Explanation
Direction: Match Column I with Column II.
68.
68.
Answer/Explanation
69. State one basic difference between a physical change and a chemical change. [CBSE 2011]
Answer/Explanation
70. What is meant by a chemical reaction? [CBSE 2011]
Answer/Explanation
71. On what basis is a chemical equation balanced?
Answer/Explanation
72. Balance the given chemical equation:
Al(s) + CuCl2(ag) → AlCl(aq) + Cu(s)
Al(s) + CuCl2(ag) → AlCl(aq) + Cu(s)
Answer/Explanation
73. Balance the given chemical equation:
Answer/Explanation
74. Balance the given chemical equation:
Answer/Explanation
75. AgNO3(aq) + NaCl(aq) → AgCl(g) ↓ + NaNO3(aq)
FeS + H2SO4 → FeSO4 + H2S ↑
Consider the above mentioned two chemical equations with two different kinds of arrows ( ↑ and ↓) along with product. What do these two different arrows indicate? [CBSE 2011]
FeS + H2SO4 → FeSO4 + H2S ↑
Consider the above mentioned two chemical equations with two different kinds of arrows ( ↑ and ↓) along with product. What do these two different arrows indicate? [CBSE 2011]
Answer/Explanation
76. Hydrogen being a highly inflammable gas and oxygen being a supporter of combustion, yet water which is a compound made up of hydrogen and oxygen is used to extinguish fire. Why? [CBSE 2011]
Answer/Explanation
77. What happens chemically when quicklime is added to water filled in a bucket?
Answer/Explanation
78. What change in colour is observed when white silver chloride is left exposed to sunlight? State the type of chemical reaction in this change.
Answer/Explanation
79. How will you define a reducing agent?
Answer/Explanation
80. Potato chips manufacturers fill the packet of chips with nitrogen gas. Why? [DoE]
Answer/Explanation
81. Why do gold and platinum not corrode in moist air?
Answer/Explanation
82. Write two characteristics associated with rancid food.
Answer/Explanation
83. How will you indicate the following effect in a chemical equation? A solution made in water.
Answer/Explanation
84. Give reason for the following:
The burning of natural gas is an exothermic reaction.
The burning of natural gas is an exothermic reaction.
Answer/Explanation
85. Give one example of a redox reaction which is also a combination reaction.
Answer/Explanation
86. Balance the given chemical equation:
HNO3 + Ca(OH)2 → Ca(NO3)2 + H2O
HNO3 + Ca(OH)2 → Ca(NO3)2 + H2O
Answer/Explanation
Fill in the Blanks
1. The addition of oxygen to a substance is called …………. whereas removal of oxygen is called …………. .
2. The addition of hydrogen to a substance is called …………. whereas removal of hydrogen is called …………. .
3. Precipitation reactions produce insoluble …………. .
4. Reactions in which energy is given out are known as …………. .
5. Reaction in which an element displaces another element from its compound is called …………. .
6. Two antioxidants which are usually added to fat and oil containing foods to prevent rancidity, are …………., …………. .
7 …………. is the process in which metals are eaten up gradually by the action of air, moisture or a chemical on
their surface.
8. 2 FeSO4 → Fe2O3 + SO2 + ………….
9. Na2SO4 + BaCl2 → …………. + 2NaCl
10. 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)
2. The addition of hydrogen to a substance is called …………. whereas removal of hydrogen is called …………. .
3. Precipitation reactions produce insoluble …………. .
4. Reactions in which energy is given out are known as …………. .
5. Reaction in which an element displaces another element from its compound is called …………. .
6. Two antioxidants which are usually added to fat and oil containing foods to prevent rancidity, are …………., …………. .
7 …………. is the process in which metals are eaten up gradually by the action of air, moisture or a chemical on
their surface.
8. 2 FeSO4 → Fe2O3 + SO2 + ………….
9. Na2SO4 + BaCl2 → …………. + 2NaCl
10. 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)
No comments:
Post a Comment