CBSE Class 10 Science Acids bases and salts Sure Shot Questions A

ACIDS, BASES AND SALTS

Question. Alkali is a base that is :
(A) soluble in alcohol.
(B) insoluble in alcohol.
(C) soluble in water.
(D) insoluble in water.
Answer : C

Question. When CO₂ is passed through lime water, it turns milky. The milkiness is due to the formation of -
(A) CaCO₃
(B) Ca(OH)₂
(C) H₂O
(D) CO₂
Answer : A

Question. 10 mL of 0.1 N HCl is added to 990 mL solution of NaCl. The pH of the resulting solution is-
(A) zero
(B) 3
(C) 7
(D) 10
Answer : B

Question. The pH of 0.1M solution of the following increases in the order of :
(A) NaCl < NH4Cl < NaCN < HCl
(B) HCl < NH4Cl < NaCl < NaCN
(C) NaCN < NH4Cl < NaCl < HCl
(D) HCl < NaCl < NaCN < NH4Cl
Answer : B

Question. Behaviour of hydrogen gas towards litmus paper is -
(A) neutral behaviour
(B) turns red litmus to blue
(C) turns blue litmus to red
(D) litmus paper starts burning
Answer : A

Question. Metal carbonates and hydrogen carbonates react with acids to give -
(A) Carbon dioxide gas
(B) Hydrogen gas
(C) Sulphur dioxide gas
(D) Carbon monoxide gas.
Answer : A

Question. Most of the metals combine with dilute acids -
(A) To produce carbon di oxide gas
(B) To form a base.
(C) To liberate hydrogen gas by displacing hydrogen from the acids
(D) To form acidic salt.
Answer : C

Question. Universal indicator is -
(A) the indicator that changes its colours at different iodide ion concentration.
(B) the indicator that shows different colours at different hydrogen ion concentrations.
(C) is effective only at low hydrogen ion concentration.
(D) gives same colour at different pH.
Answer : B

Question. Fresh milk has a pH of 6. On changing into curd, its pH becomes -
(A) more than 6.
(B) less than 6.
(C) remains 6.
(D) 7.
Answer : B

Question. Which of the following aqueous solutions will have highest pH ?
(A) Sodium acetate
(B) Sodium chloride
(C) Ammonium phosphate
(D) Calcium chloride
Answer : A

Question. The pH of a compound is found to be 9. The compound can be -
(A) HCl.
(B) NaOH.
(C) Na₂CO_3.
(D) CH₃COOH.
Answer : C

Question. pH of pure water is -
(A) 0
(B) 1
(C) 7
(D) 14
Answer : C

Question. If pH of solution is 13, means that it is -
(A) weakly acidic
(B) weakly basic
(C) strongly acidic
(D) strongly basic
Answer : D

Question. Which is an acidic indicator ?
(A) phenolphthalein
(B) methylorange
(C) (A) & (B) both
(D) none of these
Answer : A

Question. The chemical formula of 'Rock salt' is -
(A) Na₂CO₃
(B) NaCl
(C) NaHCO₃
(D) KCl
Answer : B

Question. Which of the following has the highest pH ?
(A) Distilled water
(B) 1 M NH₃
(C) 1 M NaOH
(D) Water saturated with chlorine
Answer : C

Question. [OH–] in a solution is 1 mol L–1. The pH of the solution is -
(A) 1
(B) 0
(C) 14
(D) 10–14
Answer : C

Question. pH of an aqueous solution is 5.5. The hydroxyl ion conc. in the solution would be -
(A) –5.5 M
(B) – 8.5 M
(C) 10–8.5 M
(D) 108.5 M
Answer : C

Question. Two solutions A and B have pH Value 2 and 5 respectively their natue will be:
(A) A and B both acidic
(B) A alkaline, B acidic
(C) B alkaline, A acidic
(D) A and B both alkaline
Answer : A

Question. Which of the following salts does not contain water of crystallization?
(a) Blue vitriol
(b) Baking soda
(c) Washing soda
(d) Gypsum
Answer : B

Question. What happens when a solution of an acid is mixed with a solution of a base in a test tube?
(i) The temperature of the solution increases
(ii) The temperature of the solution decreases
(iii) The temperature of the solution remains the same
(iv) Salt formation takes place
(a) (i) only
(b) (i) and (iii)
(c) (ii) and (iii)
(d) (i) and (iv)
Answer : D

Question. Which one of the folIowing reaction is not possible: 
(A) Ca + HVSO₄ → CaSO₄ + H₂
(B) Cu + H₂SO₄ →CuSO₄ + H₂
(C) Zn + H₂SO₄ → ZnSO₄ + H₂
(D) Mg+ H₂SO₄ → MgSO₄ + H₂
Answer : B

Question. Which of the following is not a property of an acid ?
(A) Acids are sour in taste.
(B) Acids turn blue litmus red.
(C) Acids don't react with active metals to give hydrogen.
(D) Acids show neutralization reaction with bases.
Answer : C

Question. Which of the following salts when dissolved in water would give acidic solutions (s) ?
(A) Na₂SO₄
(B) (NH₄)₂SO₄
(C) CH₃COONa
(D) KCl
Answer : B

Question. 10^–3 mole of KOH is added to 10 litres of pure water at 25°C. The pH will change by (assume no change in volume occurs)
(A) 3
(B) 4
(C) 7
(D) 11
Answer : A

Question. On reacting a compound of calcium (x) with water compound (y) is obtained. (y) on boiling with NH4Cl a gas (z) is obtained. x, y & z respectively are :
(A) CaCO₃, CaO, NH₃
(B) CaCO₃, CaO, Cl₂
(C) CaO, CaCl₂, Cl₂
(D) CaO, Ca(OH)₂, NH₃
Answer : D

Question. An aqueous solution turns red litmus solution blue. Excess addition of which of the following solution would reverse the change?
(a) Baking powder
(b) Lime
(c) Ammonium hydroxide solution
(d) Hydrochloric acid
Answer : D

Question. Plaster of paris hardens by:
(A) Losing CaCI₂
(B) Absorbing CO₂
(C) Absorbing water
(D) Releasing water
Answer : C

Question. Basic radical is: 
(A) Positively Charged ion
(B) Negatively charged ion
(C) Neutral atom
(D) None of the above
Answer : A

Question. Sodium carbonate is a basic salt because it is a salt of
(a) strong acid and strong base
(b) weak acid and weak base
(c) strong acid and weak base
(d) weak acid and strong base
Answer : D

Question. During the preparation of hydrogen chloride gas on a humid day, the gas is usually passed through the guard tube containing calcium chloride. The role of calcium chloride taken in the guard tube is to
(a) absorb the evolved gas
(b) moisten the gas
(c) absorb moisture from the gas
(d) absorb Cl– ions from the evolved gas
Answer : C
 

ASSERTION REASON TYPE QUESTIONS

For the following question numbers (1-5) two statements are given- one labeled Assertion (A) and the other labeled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below:
a) Both A and R are true, and R is correct explanation of the assertion.
b) Both A and R are true, but R is not the correct explanation of the assertion.
c) A is true, but R is false.
d) A is false, but R is true

Question. Assertion: Plaster of Paris is a is a white powder used to join fractured bones
Reason: On mixing with water plaster of paris changes to Gypsum giving a solid hard mass
Answer: A

Question. Assertion: Our stomach produces Sulphuric acid, which helps in digestion of food.
Reason: During indigestion excess acid secreted is neutralized by using bases called antacids.
Answer: D

Question. Assertion: Sodium Hydroxide is formed during Chlor-alkali process
Reason: Electricity is passed through Sodium Hydroxide during chlor- alkali process.
Answer: C

Question. Assertion: After white washing the walls, a shiny white finish on walls is obtained after two to three days.
Reason: Calcium Oxide reacts with Carbon dioxide to form Calcium Hydrogen Carbonate which gives shiny white finish.
Answer: A

Question. Assertion: Baking soda is used for making food substances crispy during cooking.
Reason: The chemical name of baking soda is Sodium hydrogencarbonate
Answer: B
 

Very Short Answer type Questions

Question. What is acid rain?
Answer: When the pH of the rain water is less than 5.6, it is called acid rain

Question. Name the substance which is used to make food articles crispy, write its chemical formula
Answer: Baking powder or Baking soda, NaHCO₃

Question. What is brine?
Answer: Concentrated solution of sodium chloride is called brine

Question. Write the formula of a salt in which water of crystallization is present.
Answer: CuSO₄. 5H₂O , Na₂CO₃.10H₂O or any other correct salt

Question. What are alkali?
Answer: Water soluble bases are called alkali

Question. Write the chemical name and chemical formula of the salt used to remove permanent hardness of water
Answer: Sodium carbonate decahydrate Na₂CO₃. 10H₂O

Question. Name a salt which is used as soda –fire extinguisher, write its chemical formula
Answer: Sodium Hydrogencarbonate (NaHCO₃)

Question. Write the chemical name and chemical formula of washing soda?
Answer: Sodium carbonate decahydrate Na₂CO₃. 10H₂O

Question. Write any one use of Chlorine
Answer: In water treatment and making pesticides (any other suitable use)

Question. Write the chemical name and chemical formula of a salt which is used for disinfecting drinking water to make it germ free
Answer: Calcium oxychloride, CaOC_l2

1. Name two natural indicators.

2. Name two indicators that are usually used in chemical laboratories to indicate acidic/basic nature of a solution.

3. What is the general name of bases that are soluble in water?

4. What is an acid?

5. Define base

6. What is the action of an acid on blue litmus paper?

7. Name two natural substances that contain acid.

8. What is the oxide of a metal called?

9. Are all bases alkalis?

10. Which type of substance is used to indicate an acid or a base?

11. What is the common element present in all acids?

12. Give the name and formula of two mineral acids.

13. Common salt contains a substance which is hygroscopic. Name the substance and write its formula.

14. Name any two organic acids.

15. What is the common to all bases?

16. Name two sources of common salt.

17. How do metals react with acid?

18. Name two metals that react with a base to produce hydrogen gas.

19. Which gas is evolved when sodium carbonate reacts with hydrochloric acid?

20. What happens when carbon dioxide gas is passed into lime water?

21. Name a sodium compound which loses its water of crystallization on exposure to air.

22. A compound of metal is obtained mainly from sea water. Write the name and formula of the compound.

23. What is the common name and formula of sodium hydroxide?

24. What is the reaction called in which an acid and a base nullify the effect of each other?

25. Name the salt which was an important symbol in India’s struggle for freedom?

26. Name a sodium compound used as a cleansing agent for domestic purposes.

27. Why does and aqueous solution of an acid conduct electricit?

28. The pH of a solution is 4. What is the nature of the solution?

29. A solution reacts with crushed egg-shells to give a gas that turns lime water milky. Say, whether the solution contains an acid or a base.

30. Which type of medicine is used to treat indigestion?

31. Which compound of a metal is a constituent of many dry soap powders?

32. Name the acid which is used as a bathroom cleaner.

33. What is the action of litmus on an aqueous solution of ammonium chloride

34. Why is a basic substance used to treat a honey-bee sting?

35. A solution turns blue litmus re. What is it pH value?

36. Which one is more acidic, pH = 2 or pH = 5?

37. Which one of the two solutions is more basic, pH = 8 or pH = 11?

38. What is the nature of the salt which dissolves in water to produce a solution which turns blue litmus to red?

39. A milkman adds some baking soda to fresh milk. How will the pH of the fresh milk change?

40. What is the pH of a solution which is neither acidic nor basic?

41. What is the chemical formula of common salt?

42. Name the process by which sodium hydroxide is made by electrolysis of brine?

43. Give the chemical name and formula of washing soda?

44. Mention the property of sodium carbonate that makes it useful as an ingredient for dry soap powders.

45. Name the carbonate of a metal which is soluble in water.

46. What is soda ash?

47. State whether the aqueous solution of washing soda is acidic or alkaline?

48. Name the substance which on being treated with chlorine yields bleaching powder.

49. Write the chemical formula of plaster of paris.

50. Write an equation to show the reaction between plaster of paris and water.

51. Write the chemical formula of quicklime.

52. Name a compound of calcium which is used for whitewashing.

53. Which compound of calcium is used for making cement and glass?

54. Write an equation to show the reaction between quicklime and water.

55. Which compound of calcium is used to produce limelight?

56. Write the chemical name and formula of baking soda?

57. Name a compound of sodium which is used in fire extinguisher.

58. Write the chemical name and formula of bleaching powder?

59. Two solutions have pH number 4 and 9 respectively which solution has more H+ ion concentration?

60. Which compound of calcium is used for disinfecting water?

61. Why should cured and sour substances not be kept in brass and copper vessel?

62. Name a compound of calcium which hardens on being mixed with water.

63. Write down the molecular formula for one strong and one weak acid.

64. Explain why plaster of Paris should be stored in a moisture proof container?

65. Name the gas evolved when dil. sulphuric acid acts on sodium carbonate.

66. What is the use of common salt in soap industry?

67. Which compound of calcium is used in paper and textile industries?

68. What do you observe when a burning candle is brought near the test-tube containing hydrogen gas?

69. Name the indicator used to measure pH values over the whole range.

70. A white, solid substance is used to disinfect water, and it makes wool shrink-proof. Name the substance.

71. How many water of crystallization an present in copper sulphate crystals

72. Write the name and formula of a compound which contains ten molecules of water of crystallization?

73. Name a sodium compound which is used in softening hard water.

74. A white powdery substance smells of chlorine and is used for disinfecting drinking water. What is the name of substance?

75. What happen when anhydrous copper sulphate is moistened with water?

76. Name the substance produced by the action of chlorine on dry slaked lime.

77. Name the compound of calcium used for bleaching cloth.

78. A compound is used to make casts for statues and for holding broken limbs and joints in place. What is this compound?

79. Write chemical equation to represent the action of dilute hydrochloric acid on bleaching powder?

80. Represent the reaction between plaster of paris and water in the form of an equation.

SHORT ANSWER TYPE QUESTIONS

1. What is an acid? Give some examples of organic and inorganic acids.

2. What is a base? Give examples?

3. What is an indicator? Give some examples of indicators?

4. What is litmus?

5. Describe some natural acid-base indicators, other than litmus.

6. What are olfactory indicators?

7. What do you mean by concentrated and dilute acid solutions?

8. Explain why brass and copper vessels are not used to keep curd and sour substances?

9. Name the gas which is liberated when metals react with an acid. Give an example. How is the presence of the gas tested?

10. HCL, HNO₃ etc. show acidic behavior in aqueous solutions but aqueous solutions of alcohol and glucose do not behave like acids. Explain why?

Please click the link below to download pdf file of CBSE Class 10 Science Acids bases and salts Sure Shot Questions A.