REDOX REACTIONS AND ELECTROCHEMISTRY – 2

1) Mg2+ ion is … than Al3+.
a) A stronger Lewis acid
b) A stronger Lewis base
c) A weaker Lewis acid
d) A weaker Lewis base

2) Which is not a conjugate pair of acid-base ?
a)
b)
c)
d)

3) Electrophiles are
a) Lewis acids
b) Lewis bases
c) Bronsted bases
d) Bronsted acids

4) Nucleophiles are
a) Lewis acids
b) Lewis bases
c) Bronsted bases
d) None

5) The conjugate base of the weak acid in the reaction HBr + H2O H3O++ Br is
a) HBr
b)
c)
d)

6) Which one is a hard base ?
a)
b)
c)
d)

7) In the reaction, AlCl3 + Cl [AlCl4], AlCl3 acts as a
a) Salt
b) Lewis base
c) Lewis acid
d) Bronsted acid

8) Which one is not an aprotic solvent ?
a)
b)
c)
d) Ethanol

9) The strength of an acid depends upon its tendency to
a) Accept protons
b) Donate protons
c) Release electrons
d) To lose electrons

10) The increasing order of acidic character of the following is
a)
b)
c)
d)

11) A certain weak acid has a dissociation constant 1.0 x 10-4. The equilibrium constant for its reaction with a strong base is
a)
b)
c)
d)

12) If Ka for a weak acid is 10-5 , the pKb value of its conjugate base is
a) 5
b) 6
c) 7
d) 9

13) The dissociation constants of two weak acids are k1 and K2. The relative strengths of the two acids is given by
a)
b)
c)
d)

14) The degree of ionisation of a solution does not depend upon the
a) Temperature
b) Nature of electrolyte
c) Nature of the solvent
d) Depends upon all these

15) The conjugate base of NH ion is
a)
b)
c)
d)

16) The equilibrium constant for NH3 + H 2O NH4+ + OH is decreased in the presence of the
a)
b)
c)
d) NaCl

17) Which is an acid salt?
a)
b) BiOCl
c) Pb(OH)Cl
d)

18) Which is an acid salt?
a)
b) NaHS
c)
d)

19) An example of a double salt is
a)
b)
c) Hypo
d) Potash alum

20) The increasing order of strength of the following bases is
a)
b)
c)
d)

21) Tetramine copper (II) sulphate in an example of a
a) Simple salt
b) Double salt
c) Complex salt
d) Normal salt

22) The conjugate base of H2SO4 in, the reaction, H2SO4+ H2O H3O+ + HSO is:
a)
b)
c)
d)

23) The conjugate acid of is
a)
b)
c)
d)

24) Which is not a Lewis acid ?
a)
b)
c)
d) RMgX

25) Which statement is correct ?
a) An acid and its conjugate base react to form salt and water
b)
c) The conjugate base of a weak acid is a strong base
d) The conjugate base of a strong acid is a strong base

26) If the pKb for the fluoride ion at 25o C is 10.83, the ionisation constant of hydrofluoric acid in water at this temperature is
a)
b)
c)
d)

27) The strongest conjugate base results from
a) Formic acid
b) Benzoic acid
c) Acetic acid
d) Acetylene

28) The aqueous solution of which salt has the lowest pH ?
a) NaOH
b)
c)
d) NaCl

29) The pH of blood is
a) 7.0
b) 7.4
c) 6.4
d) 14

30) The pH of K2S solution is.
a) >7
b) <7
c) 7
d) Zero

31) The pH of rain water (pure) is
a) Zero
b) 7
c) 3
d) 10

32) Soda water has a pH value of
a) <7
b) >7
c) 7
d) Greater than 14

33) The addition of which salt decreases the H+ ion concentration of HCN solution?
a)
b)
c)
d) NaCN

34) The pH of water at 25°C is 7.0. If water is heated to 70°C, the
a) pH will increase
b) pH will decrease
c) pH will remain same
d) None

35) The addition of HCl does not suppress the ionisation of
a)
b)
c) H2SO4
d) NaCl

36) At 90°C pure water has H3O+=10-6 mole litre-1. The value of Kw at 90°C is
a)
b)
c)
d)

37) The pH of water at 298 K is close to
a) 2
b) 7
c) 10
d) 11

38) Which aqueous solution will have a pH less than 7 ?
a)
b) NaOH
c) NaCN
d)

39) The pH of blood is maintained by CO2 and H2CO3 in the body and the chemical constituents of blood. This is called
a) Colloidal action
b) Buffer action
c) Acidic action
d) Salt balance

40) What happens to the pH of the solution when HCl gas is added to H2S solution ?
a) The pH increases
b) The pH decreases
c) The pH remains constant
d) None

41) What happens to the pH of a solution when NH4Cl crystal is added to a dilute solution of ammonia?
a) It decreases
b) It increases
c) it remains constant
d) All

42) Which one of the following will have the highest ph value ?
a) An acid solution
b) A basic solution
c) A slightly basic solution
d) Neutral solution

43) The most important buffer in the blood consists of
a)
b)
c)
d)

44) The following reactions are known to occur in the body.

CO2 + H2O H2CO3 H+ +HCO If CO2 escapes from the system, then.
a) the pH will decrease
b)
c)
d) The forward reaction will be promoted

45) On adding solid KCN to water,the
a) pH increases
b) pH decreases
c) pH does not change
d) None

46) A buffer solution is a mixture of
a) A strong acid and a strong base
b) A weak acid and its conjugate acid
c) A weak acid and its conjugate base
d) All

47) The pH value of the tears coming out of a persons eye is
a) 7.4
b) 6.4
c) 7.0
d) 2.4

48) The pH of gastric juice is normally.
a) Greater than 1.5 and less than 1.2
b) Less than 1.5
c) Greater than 1 and less than 3
d) Less than 1 and greater than zero

49) The pH of blood is
a) <6
b) >7 but <8
c) >8 but <9
d) >10

50) The pH of solutions A, B, C, D are 9.5, 2.5,3.5 and 5.5 respectively. The most acidic solution is
a) A
b) B
c) C
d) D

51) The unit of the ionic product of water is
a)
b)
c)
d)

52) The pH of 0.1 M solution of the following increases in the order
a)
b)
c)
d)

53) The buffer solutions play an important role in
a) Increasing the pH value
b) Decreasing the pH value
c) Keeping the pH constant
d) None of these

54) The pH of 10M HCl in aqueous solution is
a) Less than zero
b) 1
c) 2
d) Zero

55) The following equilibrium exists in aqueous solution. CH3COOH H+ + CH3COO. If
dilute HCl is added to this solution,

a) The equilibrium constant will increase
b) The equilibrium constant will decrease
c) The acetate ion concentration will decrease
d) The acetate ion concentration will increase

56) Acidosis is diagnosed when the pH of the blood
a) Decreases below 7.35
b) Increases above 7.45
c) Both (a) and (b)
d) None

57) Which of the following is involved in the digestion process ?
a) HF
b) HCl
c) HBr
d) HI

58) In an aqueous solution of ammonia the OH ion concentration ….. on addition of NH4Cl.
a) Increases
b) Decreases
c) Does not change
d) None

59) In the dissociation,

H2A H+ + HA (K1)

HA H+ + A2- (K2)
a)
b)
c)
d)

60) When pH of a solution decreases, its H+ ion concentration
a) Decreases
b) Increases
c) Rapidly increases
d) Remains always constant

61) Which cannot act as a buffer ?
a) NH4Cl+NH3
b)
c) 40 ml of 0.1M NaCN + 20 ml of 0.1M HCl
d) NaOH+CH3COOH in 1:1 molar ratio.

62) A solution which is resistant to pH changes on the addition of small amounts of acid or base is called a
a) Buffer solution
b) Indicator
c) Crystalloid
d) Colloid

63) An alkaline solution has [H+]
a)
b)
c)
d)

64) An acidic buffer mixture can be prepared by mixing
a) Formic acid and sodium formate
b) HCl and NaCl
c) NaOH and NaCl
d) NH4Cl and aqueous ammonia

65) A solution of NaCl in contact with the atmosphere has a pH of about
a) 3.2
b) 5.4
c) 7.0
d) 14

66) The aqueous solution of which has the lowest pH ?
a) NaCl
b)
c)
d)

67) Addition of NH4Cl to NH4OH results in
a)
b)
c)
d) None

68) A solution with equal pH and pOH is called a
a) Dilute solution
b) Protonic solution
c) Neutral solution
d) Buffer solution

69) Buffer solutions have
a) Reserve acidity
b) Reserve alkalinity
c) pH equal to zero
d) Stable pH

70) The relation for calculating the pH of a weak base is
a)
b)
c)
d) None

71) The Hendersons equation used to calculate the pOH of a basic buffer is
a)
b)
c)
d)

72) Which of the following will have a pH < 7 on reaction with water ?
a)
b) CaO
c)
d) BaO

73) The isoelectric point is defined as the pH at which
a) An amino acid becomes acidic
b) An amino acid becomes basic
c) A Zwitter ion has positive charge
d) A Zwitter ion has zero charge

74) The dissociation constants of a weak acid and a weak base constituting the salt are the same. The pH of a solution of the salt is
a) 7
b) > 7
c) < 7
d) Zero

75) The OH ion concentration of a weak base is
a)
b)
c)
d)

76) The pH of an acidic buffer mixture is
a) > 7
b) < 7
c) = 7
d) Dependent upon the Ka of the acid

77) Which of the following is correct ?
a) Upon hydrolysis tthe salt of a strong base and a weak acid gives a solution with pH<7
b)
c)
d)

78) The pH of the solution formed by mixing 40 ml of 0.10 M HCl with 10 ml of 0.45 M of NaOH is
a) 10
b) 12
c) 8
d) 6

79) The degree of ionisation increases
a) With the increase in concentration of solution
b) On addition of water
c) On decreasing the temperature
d) On stirring the solution vigorously

80) If 1M CH3COONa is added to 1M CH3COOH, the
a) pH of the solution increases
b) pH decreases
c) pH does not change
d) None

81) Among the following, the compound which ionises almost completely in water is
a) Alcohol
b) Potassium chloride
c) Acetic acid
d)

82) In a solution of weak electrolyte at infinite dilution we have
a) Only cations
b) Only anions
c) Cations and anions
d) Cations, anions, and unionised electrolyte

83) A solution of pH 9 is.. …basic than a solution of pH 12
a) Less
b) More
c) Equally
d) None

84) The pH of H2S is
a) > 7
b) < 7
c) = 7
d) Zero

85) Which may be added to one litre of water to act as a buffer ?
a)
b)
c) 1 mol of NH4CH and 1mole of HCl
d)

86) An aqueous solution whose pH = 0 is
a) Acidic
b) Basic
c) Neutral
d) Amphoteric

87) If NaOH is added to a solution of CH3COOH
a)
b) pH decreases
c)
d)

88) @ The H+ ion concentration in a solution of weak acid (Ka) and concentration c is nearly equal to
a)
b)
c)
d)

89) A mixture of a weak acid (say CH3COOH) and its salt with a strong base (say CH3COONa) acts as a buffer. Which other pair has similar properties ?
a) HCl and NaCl
b)
c) KOH and KC1
d)

90) In the precipitation of group III in qualitative analysis, NH4Cl is added before NH4OH to
a)
b)
c)
d) None

91) Aqueous solutions of two acids having same concentration of common H+ ions are called
a) Isohydric solutions
b) Isotonic solutions
c) Isomeric solutions
d) Hypotonic solutions

92) The pH of a solution of salt undergoing anionic hydrolysis (say CH3COONa) is
a)
b)
c)
d) None

93) Which does not contribute significantly to acid rain ?
a)
b)
c)
d) CO

94) Which of the following solutions does not act as a buffer ?
a)
b)
c)
d)

95) In a buffer solution containing a weak acid and its salt, the ratio of concentration of the salt to acid is increased tenfold. Then the pH of the solution will
a) Increase by one
b) Increase ten fold
c) Decrease by one
d) Decrease ten fold

96) Fear or excitement, generally causes one to breathe rapidly and it results in a decrease
in the concentration of CO2 in the blood. In what way will it change the pH of the blood ?

a) The pH will increase
b) The pH will decrease
c) There is no change
d) The pH will be seven

97) The pK a of acetyl salicylic acid (aspirin) is 3.5. The pH of gastric juice in human stomach is about 2-3 and the pH in the small intestine is about 8. Aspirin will be
a) Un-ionised in the small intestine and in the stomach
b) Completely ionised in the small intestine and in the stomach
c) Ionised in the stomach and almost un-ionised in the small intestine
d) Ionised in the small intestine and un-ionised in the stomach

98) The pH value of 0.0001 M HCl is
a) 2
b) 3
c) 4
d) 1

99) What is the pH of a solution having an H+ ion concentration of 3.3 x 10-11M ?
a) 10.4815
b) 8.5
c) 8.4815
d) 6.4

100) The pH of a solution is 5.4. Its [H+] in moles/litre is
a)
b)
c)
d)


Answer :

Leave a Reply

Your email address will not be published. Required fields are marked *