Chapter 7 : ACIDS, BASES AND SALTS

Choose Appropriate Alternative

1. What is formed by the reaction of a non-metal oxide with water?
   

   [A] Acid [B] Base [C] Salt [D] Metal

2. Acid + Metal oxide ---> ______
   

   [A] Base + water [B] Salt + water [C] Base + salt [D] Metal + salt

3. Which gas is produced by the reaction of a base with a metal?
   

   [A] Carbon dioxide [B] Dioxygen [C] Dihydrogen [D] Dinitrogen

4. 500 ml aqueous solution is prepared by dissolving 2 moles of HCl in water. What will be the molarity of this solution?
   

   [A] 1 [B] 2 [C] 3 [D] 4

5. What is correct for acidic aqueous solution?
   

   [A] [H3O+] = 10-7M [B] [H3O+] < 10-7M [C] [H3O+] > 10-7M [D] [H3O+] < [OH-]

6. Which of the following solutions is most basic?
   

   [A] pH = 8.2 [B] pH = 9.3 [C] pH = 11.5 [D] pH = 10.6

7. Which of the following statements is incorrect?
   

   [A] pH scale was presented by S.P.L.Sorensen. 
   [B] pH scale ranges from 0 to 14.
   [C] pH scale is applicable to only non-aqueous solutions.
   [D] pH scale is applicable to only aqueous solutions.

8. What is used to measure the exact p^H of an aqueous solution?
   

   [A] pH paper [B] Litmus paper [C] pH meter [D] Universal indicator

9. Which of the following substances is an antacid?
   

   [A] NaCl [B] Mg(OH)2 [C] HCl [D] H2SO4

10. How many times less basic is an aqueous solution having p^H = 11 than that having p^H = 8?
    

    [A] 3 [B] 30 [C] 300 [D] 1000

11. Which of the following is a strong acid?
    

    [A] Acetic acid [B] Citric acid [C] Nitric acid [D] Oxalic acid

12. What type of substance is NH₃?
    

    [A] Strong acid [B] Weak acid [C] Strong base [D] Weak base

13. p^H + p^OH = ______.
    

    [A] 7 [B] 0 [C] 14 [D] 10

14. Which of the following formulas is correct?
    

    [A] Mole = molecular mass/weight [B] Mole = weight /molecular mass 
    [C] Mole = weight/litre       [D] Mole = molecular mass/litre

15. What will be the p^H of aqueous solution of NH₄Cl?
    

    [A] pH = 7 [B] pH > 7 [C] pH < 7 [D] pH = 0

16. Which of the following solutions will have p^H = 2?
    

    [A] 0.01M HCl [B] 0.02M HCl [C] 0.01M H2SO4 [D] 0.02M H2SO4

17. What will be the concentration of OH^- ion in aqueous solution having p^H = 8?
    

    [A] 1 x 10-8M [B] 1 x 10-6M [C] 8 x 10-6M [D] 8 x 10-8M

18. The p^H values of solutions A, B, C and D are 1.9, 2.5, 2.1 and 3.0, respectively. Their order of acidity will be...
    

    [A] A < C < B < D [B] D < C < B < A [C] D < B < C < A [D] D > C > B > A

19. Which solution will be basic?
    

    [A] [H3O+] = 10-5M [B] [H3O+] = 10-12M
    [C] [H3O+] = 10-7M [D] [H3O+] = 10-4M

20. Which substance is present in the poison of honey bee?
    

    [A] Lime [B] Calcium phosphate [C] Mellitin [D] Pepsin

21. Who gave operational definitions of acids and bases?
    

    [A] Robert Boyle [B] Arrhenius [C] Bronsted-Lowry [D] Sorensen

22. Who gave acid-base theory based on the process of ionization?
    

    [A] Robert Boyle [B] Arrhenius [C] Bronsted-Lowry [D] Lewis

23. According to Arrhenius, base is a substance producing _____ ion in aqueous solution.
    

    [A] H+ [B] OH- [C] H3O+ [D] K+

24. Which of the following does not have independent existence?
    

    [A] H+ [B] H2 [C] H3O+ [D] NH3

25. According to Bronsted-Lowry, an acid is a substance which...
    

    [A] accepts proton from another substance [B] donates proton to another substance 
    [C] does not ionize [D] does not produce OH- ion in aqueous solution

26. According to Bronsted-Lowry, a base is a substance which...
    

    [A] does not form covalent bond [B] accepts proton from another substance
    [C] ionizes completely         [D] donates proton to another substance

27. The bond between H⁺ and H₂O in H₃O⁺ is...
    

    [A] ionic [B] covalent [C] coordinate covalent [D] metallic

28. According to Bronsted-Lowry, when HCl gas is dissolved in water, water behaves as...
    

    [A] an acid [B] a base [C] a neutral substance [D] a salt

29. According to Bronsted-Lowry, when ammonia gas is dissolved in water, water behaves as...
    

    [A] an acid [B] a base [C] a neutral substance [D] a salt

30. According to the acid-base theory by Bronsted-Lowry, water is...
    

    [A] an acid [B] a base [C] amphoteric [D] neutral

31. The formula of carbonic acid is...
    

    [A] H2SO3 [B] CO2 [C] H2CO3 [D] HCO3

32. Which of the following gives an acid when dissolved in water?
    

    [A] NH3 [B] Na2O [C] CaO [D] SO3

33. Which of the following gives a basic solution when dissolved in water?
    

    [A] CO2 [B] SO2 [C] SO3 [D] Na2O

34. Which of the following metals generally do not react with acids?
    

    [A] Au [B] Ag [C] Pt [D] All three

35. Which of the following metals easily reacts with an acid?
    

    [A] Ca [B] Au [C] Ag [D] Pt

36. When nitric acid reacts with a metal like zinc,______ gas is produced.
    

    [A] NO2 [B] H2 [C] NO [D] N2O

37. The reaction between an acid and a base is called...
    

    [A] acid hydrolysis [B] hydrolysis [C] alkalisation [D] neutralization

38. When an acid reacts with a metal carbonate/bicarbonate _____ gas is produced.
    

    [A] CO2 [B] CO [C] CO2 or CO [D] both CO2 and CO

39. The formula of sodium zincate is...
    

    [A] NaZn2O4 [B] Na2ZnO2 [C] NaZnO3 [D] Na2Zn2(OH)3

40. The unit of molarity is...
    

    [A] mole/kg [B] kg/mole [C] mole/litre [D] kg/litre

41. The molecular mass of NaOH is 40 g/mole. How much NaOH is required to prepare 250 ml 1M solution of NaOH?
    

    [A] 10g [B] 40g [C] 160g [D] 100g

42. The molecular mass of H₂SO₄ is 98. If 29.4g H₂SO₄ is dissolved in water to make 500 ml solution, what is its molarity?
    

    [A] 0.3M [B] 0.6M [C] 0.15M [D] 0.5M

43. When 112g of KOH is dissolved in water to make 4 litre solution, its molarity is 0.5M. What is the molecular mass of KOH?
    

    [A] 112 [B] 224 [C] 56 [D] 28

44. The formula for the p^H of an aqueous solution is...
    

    [A] pH = log10 [H3O+] [B] pH = -log10 [H3O+]
    [C] pH = log10 [OH-][D] pH = -log10 [OH-]

45. At 298 K, the concentration of H₃O⁺ in pure water is...
    

    [A] 1 x 10-7M [B] 1 x 107M [C] 7.0M [D] 0.7M

46. If the colour of p^H paper turns pink in an aqueous solution, then the approximate p^H of the solution is...
    

    [A] 8 [B] 6 [C] 4 [D] 2

47. If the colour of p^H paper turns blue in an aqueous solution, then the approximate p^H of the solution is...
    

    [A] 10 [B] 8 [C] 7 [D] 5

48. The range of p^H suitable for efficient biological processes in humans is...
    

    [A] 5.6 to 6.5 [B] 6.5 to 7.0 [C] 7.0 to 7.8 [D] 7.8 to 8.7

49. The range of p^H suitable for proper activity of enzyme pepsin in stomach is...
    

    [A] 8 to 9 [B] 6 to 8 [C] 4 to 6 [D] 1 to 3

50. The range of p^H of the soil suitable for better growth and development of plants is...
    

    [A] 5.6 to 6.5 [B] 6.5 to 7.3 [C] 7.3 to 7.8 [D] 7.8 to 8.7

51. Farmers use _____ for neutralization of acidic soil.
    

    [A] CaSO4.2H2O [B] CaO [C] H2CO3 [D] CH3COOH

52. Farmers use _____ for neutralization of alkaline soil.
    

    [A] CaSO4.2H2O [B] CaO [C] NaOH [D] KOH

53. The external surface of our teeth is made up of...
    

    [A] calcium sulphate [B] calcium carbonate [C] calcium phosphate [D] calcium chloride

54. The external surface of our teeth gets corroded if the p^H within the mouth is...
    

    [A] less than 5.5      [B] between 5.5 and 7.0 
    [C] between 7.0 and 7.5 [D] beyond 7.5

55. Red ants contain _____ in their body.
    

    [A] citric acid [B] formic acid [C] acetic acid [D] oxalic acid

56. Melittin is a polypeptide consisting of _____ amino acids.
    

    [A] 20 [B] 22 [C] 24 [D] 26

57. The p^H values for two aqueous solutions 'A' and 'B' are 2 and 5, respectively. If the concentration of H₃O⁺ in 'A' is 'x' mole/lit, then the concentration of H₃O⁺ in 'B' is _____ mole/lit.
    

    [A] x/3 [B] 3x [C] 2x/5 [D] x/1000

58. If (p^H of solution A - p^H of solution B) = x, then the ratio of concentrations of H₃O⁺ in solution B and solution A is...
    

    [A] x [B] 10x [C] 10x [D] x/10

59. If (p^H of solution A - p^H of solution B) = x, then the ratio of concentrations of OH^- in solution A and solution B is...
    

    [A] x/10 [B] 10x [C] 10x [D] x

60. If the difference between p^H and p^OH of a solution is 4, then p^H = ______.
    

    [A] 10 [B] 9 [C] 8 [D] 6

61. If the difference between p^OH and p^H of a solution is 4, then p^H = ______.
    

    [A] 4 [B] 5 [C] 6 [D] 8

62. Which of the following is a weak acid?
    

    [A] Sulphuric acid [B] Nitric acid [C] Citric acid [D] Hydrochloric acid

63. The concentration of H₃O⁺ in 1 M aqueous solution of sulphuric acid is...
    

    [A] 1 M [B] 2 M [C] 0.5 M [D] 0 M

64. The concentration of SO₄^-2 in 1 M aqueous solution of sulphuric acid is...
    

    [A] 1 M [B] 2 M [C] 0.5 M [D] 0.01 M

65. The p^H of a salt solution obtained by the reaction between a strong acid and a strong base is...
    

    [A] is 7 [B] is less than 7 [C] is more than 7 [D] cannot be determined

66. Sodium chloride is a salt of...
    

    [A] a weak acid and a weak base    [B] a strong acid and a strong base
    [C] a weak acid and a strong base [D] a strong acid and a weak base

67. Which of the following is a salt of a strong acid and a strong base?
    

    [A] Na2CO3 [B] NH4NO3 [C] NH4Cl [D] KNO3

68. Which of the following is a salt of a weak acid and a strong base?
    

    [A] NaCl [B] KNO3 [C] Na2CO3 [D] NH4NO3

69. Which of the following is a salt of a strong acid and a weak base?
    

    [A] NaCl [B] Na2CO3 [C] NH4Cl [D] CH3COONH4

70. Which of the following is a salt of a weak acid and a weak base?
    

    [A] NaCl [B] KNO3 [C] Na2CO3 [D] (NH4)2CO3

71. The aqueous solution of a salt obtained by the reaction between a weak acid and a weak base is...
    

    [A] acidic [B] basic [C] neutral [D] any one of A, B and C

72. Which gas is liberated by the reaction of an acid with a carbonate?
    

    [A] H2 [B] CO2 [C] N2 [D] O2

73. The number of moles of a solute dissolved in 1 litre solution is called...
    

    [A] normality [B] molality [C] molarity [D] acidity

74. Which of the following acids is secreted in our stomach?
    

    [A] H2SO4 [B] HCl [C] HNO3 [D] Citric acid

75. A substance 'Z' ionizes completely in an aqueous solution releasing H₃O⁺ ion. The substance 'Z' is a...
    

    [A] strong acid [B] strong base [C] weak acid [D] weak base

76. NaOH is ...
    

    [A] a salt [B] a weak base [C] a strong base [D] a strong acid

77. Which of the following is the correct formula for 'mole'?
    

    [A] Molecular mass/weight [B] weight/litre [C] weight/molecular mass [D] litre/weight

78. What is the nature of an aqueous solution having p^OH = 5?
    

    [A] Acidic [B] Basic [C] Neutral [D] Amphoteric

79. What is the molecular formula of milk of magnesia?
    

    [A] Mg(OH)2 [B] MgCO3 [C] NaHCO3 [D] MgO

80. What will be the value of p^H of 10^-5 M NaOH solution?
    

    [A] 5 [B] 8 [C] 9 [D] 10

81. When blue litmus paper is dipped in an aqueous solution 'A', its colour does not change. Which of the following is true for 'A'?
    

    [A] It is neutral. [B] It is basic. [C] It is not acidic. [D] It is acidic or neutral.

82. Match the pairs from Part A and Part B
    
    
    
    

    [A] 1-q, 2-s, 3-r, 4-p [B] 1-r, 2-p, 3-q, 4-s
    [C] 1-r, 2-p, 3-s, 4-q [D] 1-q, 2-p, 3-r, 4-s

83. Match the names in Part A with appropriate formula in Part B.
    
    
    
    

    [A] 1-s, 2-p, 3-q, 4-t [B] 1-q, 2-s, 3-p, 4-t 
    [C] 1-q, 2-p, 3-s, 4-r [D] 1-r, 2-s, 3-p, 4-q

84. If there is a decrease in the concentration of H₃O⁺, what is the change in the p^H of the solution?
    

    [A] No change [B] Increase [C] Decrease [D] may increase or decrease

85. Neutralization between a weak acid and a weak base results in the formation of a _____ salt.
    

    [A] acidic [B] basic [C] neutral [D] any of these

86. 
    

    [A][B][C][D]

87. 
    

ANSWERS

(1) A (2) B (3) C (4) D (5) C (6) C (7) C (8) C (9) B (10) D (11) C (12) D (13) C (14) B (15) C (16) A (17) B (18) C (19) B (20) C (21) A (22) B (23) B (24) A (25) B (26) B (27) C (28) B (29) A (30) C (31) C (32) D (33) D (34) D (35) A (36) C (37) D (38) A (39) B (40) C (41) A (42) B (43) C (44) B (45) A (46) D (47) A (48) C (49) D (50) B (51) B (52) A (53) C (54) A (55) B (56) D (57) D (58) C (59) B (60) B (61) B (62) C (63) B (64) A (65) A (66) B (67) D (68) C (69) C (70) D (71) D (72) B (73) C (74) B (75) A (76) C (77) C (78) B (79) A (80) C (81) C (82) D (83) B (84) B (85) D (86) (87) (88) (89) (90) (91)