REDOX REACTIONS AND ELECTROCHEMISTRY – 1

1) The standard electrode potential is the electrode potential at
a) 250C and 1 atm. pressure of the metal alone
b) 250C and 1 atm. pressure of the metal in contact with its ions
c) 250C and 1 atm. pressure of the metal in contact with its ions in 1 mol L-1 of its ions
d) 250C and 1 atm pressure of the metal in contact with ions of a different metal

2) Identify the incorrect statement with respect to oxidation number:
a) The element whose O.N. does not change is Fluorine
b) In compounds, hydrogen can have O.N. other than +1
c) The sum of the O.N. of all the elements in a compound is zero
d) the oxidation number of an element in the uncombined form is zero

3) The oxidation number/s of Nitrogen atoms in NH4NO3 is/are
a) +4
b) +4,-6
c) +3,-5
d) -3,+5

4) The oxidation number of oxygen in OF2 is
a) +2
b) -2
c) -1
d) +(1/2)

5) Which of the following electrodes will act as an anode when connected with S.H.E.?
1) AI/AI3+E0= -1.66
2) Fe/Fe2+E0= -0.44
3) Cu/Cu++E0= +0.34

a) Copper only
b) Aluminium only
c) Aluminium and Iron
d) Iron and Copper

6) Which of the following reactions is /are not feasible
1. Cu + Zn2+ –> Cu2+ +Zn
2. Cu + 2H+ –> Cu2+ + H2
3. Cu + Ag+ –> Cu2+ + Ag
4. Zn + Cu2+

a) 1 and 4
b) 1, 2 and 3
c) 1 and 2
d) 1, 3 and 4

7) As per the equation NO3 + Zn ® Zn+2 + NH 4+, the number of moles of Zn required to reduce 1 mole of NO3 is
a) 1
b) 2
c) 3
d) 4

8) The oxidation numbers of potassium and oxygen in Potassium super oxide are respectively
a) 1 and +(1/2)
b) 1 and -(1/2)
c) -1 and +(1/2)
d) 1 and zero

9) Identify the incorrect statement
a) oxidation is the loss of electrons
b) reduction is the addition of electrons
c) an oxidising agent must be capable of accepting electrons
d) an oxidising agent must be capable of giving electrons

10) Fe 2+ + NO3+ H + ® Fe 3 + + NO + H2O.
The number of moles of electrons required to reduce 1 mole of NO3 to NO is
a) 1
b) 2
c) 3
d) 7

11) The oxidation number of chlorine in CIO2, CIO2, and CI F is respectively
a) 1, 3 and 4
b) 4, 3 and 1
c) -1,-3,-4
d) -4,-3 and -1

12) HNO3® NH4+. The change in oxidation number of nitrogen is
a) 2
b) 4
c) 8
d) zero

13) The EMF of the cell formed by coupling a copper electrode with a zinc electrode if E0 Cu/Cu++=0.34 V and E0 Zn++/Zn= 0.76 V
a) 1.10V
b) -0.42V
c) -1.10V
d) 0.42V

14) Water is reduced to H2 by metals whose standard reduction potentials are
a) equal to -0.41 V
b) >-0.41 V
c) <-0.41 V
d) zero V

15) An example of a Lewis base is
a) NaCl
b) Ethyl ether
c)
d)

16) Which of the following is different from the other three oxides in its acid/base properties?
a) MgO
b) SnO
c) ZnO
d)

17) The ionisation potential order for which set is correct?
a) Li>K>Cs
b) B>Li>K
c) Cs>Li>B
d) Cs<li<k< font=””>

18) The conjugate acid of HPO ion is
a)
b)
c)
d)

19) Which species would be least likely to act as a Lewis base?
a)
b)
c)
d)

20) The strongest acid is
a)
b)
c)
d)

21) The weakest base among the following is
a)
b)
c)
d) KOH

22) Which species acts as an acid and also as the conjugate base of another acid?
a)
b)
c)
d)

23) Which is the least basic?
a)
b)
c)
d)

24) The two Bronsted bases in the reaction, HC2O + PO HPO + C are
a)
b)
c)
d)

25) Arrange H2SO4 (I), H3PO4 (II) and HClO4 (III) in their decreasing order of acidic strength.
a) I > III > II
b) I > II > III
c) III > II > I
d) III > I > II

26) The conjugate acid of S2 is
a)
b)
c)
d)

27) The conjugate base of hydrazoic acid is
a)
b)
c)
d)

28) Which one is the strongest base?
a)
b)
c)
d)

29) Which one is the strongest acid?
a)
b)
c)
d)

30) Which is not a Lewis base?
a)
b)
c)
d)

31) NH3 acts as a Lewis base because it is
a) An electron pair donor
b) An electron pair acceptor
c) A proton donor
d) A proton acceptor

32) Which of the following is an acidic salt?
a)
b)
c)
d)

33) H3BO3 is
a) Monobasic
b) Dibasic
c) Tribasic
d) None

34) The correct order of increasing [H3O+] in the following aqueous solutions is
a) 0.01 MH2S<0.01MH2SO4<0.01MNaCl
b) 0.01MNaCl<0.01MH2SO4<0.01MH2S
c) <0.01MNaCl<0.01MH2S<0.01MH2SO4
d) None of the above

35) Which is not amphoteric ?
a)
b)
c)
d)

36) Which one is the strongest base?(R=alkyl)
a)
b)
c)
d)

37) Mg(OH)Cl is an example of a/an
a) Acid salt
b) Basic salt
c) Neutral salt
d) double salt

38) The acidic nature of ZnO is shown from the formation of the salt
a)
b)
c)
d) None

39) The strongest acid is
a)
b)
c)
d)

40) The conjugate base of (CH3)2NH is
a)
b)
c)
d)

41) The strongest conjugate base is
a)
b)
c)
d)

42) The weakest base among the following is
a)
b)
c)
d)

43) Which of the following is a basic salt ?
a) PbS
b)
c)
d)

44) NH3 gas is dissolved in water to give NH4OH. In this reaction water acts as
a) An acid
b) A base
c) A salt
d) A conjugate base

45) Which is not a Lewis acid ?
a)
b)
c)
d)

46) The weakest acid among the following is
a) HBr
b)
c)
d)

47) The conjugate acid of H ion is
a)
b)
c)
d)

48) The conjugate acid of SO is
a)
b)
c)
d)

49) The conjugate base of the OH ion is
a)
b)
c)
d)

50) The pKa for acid A is greater than the pKa for acid B. The stronger acid is
a) Acid A
b) Acid B
c) Both A and B
d) Neither A nor B

51) pKa values of four acids are given below at 25°C. Which indicates the strongest acid?
a) 2.0
b) 2.5
c) 3.4
d) 4.0

52) The anhydride of H3PO4 is
a)
b)
c)
d) None

53) The dissociation constant (Ka) of an acid A is more than that of B. The stronger acid is
a) Acid A
b) Acid B
c) A and B are of the same strength
d) cannot be predicted

54) According to the Bronsted Lowry concept, water is
a) An acid
b) A base
c) Neutral
d) Both an acid and a base

55) Which is an acid anhydride ?
a) BaO
b)
c)
d) CO

56) The solvent which is not a proton donor nor proton acceptor is called
a) Amphoteric
b) Neutral
c) Aprotic
d) Protonic

57) Which shows weak ionisation in water ?
a)
b)
c) NaCl
d)

58) The anhydride of H3PO4 and HPO3 are/is
a)
b)
c)
d) None

59) The conjugate acid of Zn(OH)2 is
a)
b)
c)
d) ZnO

60) The conjugate base of CH3OH is
a)
b)
c)
d)

61) The metal that reacts with both acids and alkalis to liberate hydrogen is
a) Cu
b) Ag
c) Zn
d) Hg

62) The conjugate base of H3BO3 is
a)
b)
c)
d)

63) Which of the following is not a salt ?
a) NaCl
b)
c) Slaked lime
d)

64) The aqueous solution of acetic acid contains
a)
b)
c)
d)

65) The conjugate base of [Al(H2O)3(OH)3 ] is
a)
b)
c)
d) [Al(H2O)(OH)4

66) Which of the following is the weakest base ?
a)
b)
c) CH30
d) CH3COO

67) Which does not represent a conjugate pair ?
a)
b)
c)
d)

68) The central metal ion in a complex acts as a/an
a) Lewis base
b) Lewis acid
c) Bronsted acid
d) Arrhenius acid

69) AlCl3 acts as a Lewis acid because it is
a) An electron pair donor
b) An electron pair acceptor
c) A proton donor
d) A proton acceptor

70) Although CO is neutral it shows an acidic nature on reaction with —- at high temperature and pressure.
a)
b) NaOH
c)
d) LiOH

71) A tribasic acid furnishes …. type of anions
a) 2
b) 3
c) 4
d) 1

72) According to the Bronsted Lowry concept, the correct order of strength of bases is the following:
a)
b)
c)
d)

73) Which acts as the Lewis acid in the reaction ?

SnCl2+ 2Cl SnCl4+ 2e
a)
b)
c)
d) None

74) Complete the following statement about Lewis acids correctly. All Lewis acids are not necessarily
a) Proton donors
b) Bronsted acids
c) Arrhenius acids
d) Electron pair acceptors

75) In the reaction CH3COOH+ HCl CH3COOH2+ + Cl, which is the conjugate acid of CH3COOH?
a)
b) HCl
c)
d)

76) The weakest acid among the following is
a) HF
b) HCl
c) HBr
d) HI

77) The conjugate base of the HSO ion is
a)
b)
c)
d)

78) The increasing order of base strength of the bases Cl-,CH3COO, and F is:
a)
b) F < Cl < CH3COO
c)
d) None of the above

79) Which acts as a Lewis base in the reaction, BCl3 + PH3 Cl3 B : PH3 ?
a)
b)
c) Both (a) and (b)
d) None

80) In water, the acids HClO4, HCl, H2SO4 and HNO3, exhibit the same strength as they are completely ionised in water (a base). This is called the …. effect of the solvent water.
a) Strength
b) Capacity
c) Buffer effect
d) Levelling effect

81) Group IA metals react violently with water to produce
a) Acidic solutions
b) Basic solutions
c) Neutral solutions
d) Amphoteric solutions

82) Which species acts as a stronger acid than formic acid in aqueous solution ?
a)
b)
c)
d)

83) Acidic salts on dissolution in water give
a) A basic solution
b) An acidic solution
c) An amphoteric solution
d) A neutral solution

84) Arrange H2O, H3O+ and OH in increasing order of acidic strength.
a) OH < H2O < H 3O+
b) H3O+ < H2O < OH
c) H2O < OH < H3O+
d) H3O+ < OH < H2O

85) Which among the following is not a mixed salt ?
a) Mg(OH)Cl
b)
c)
d) None of the above

86) The increasing trend of acidic nature of trihalides is
a)
b) Bl3 < BBr3 < BCl3 < BF3
c) BBr3 < BCl3 < BF3 < Bl3
d) BCl3 < < Bl3 < < BF3 < BBr3

87) The compound HCl behaves as …. in the reaction HCl + HF H2Cl ++ F.
a) A strong acid
b) A strong base
c) A weak acid
d) A weak base

88) The increasing acidic strength of HClO4, HClO3, HClO2 and HClO follows the order:
a)
b)
c)
d) None

89) Decreasing acid strength of HI, HBr, HCl and HF is
a) HF > HCl > HBr > HI
b) HI > HBr > HCl > HF
c) HI > HCl > HBr > HF
d) HI > HF > HCl > HBr

90) Which of these acts as amphoteric ?
a) HCl
b)
c)
d)

91) The oxy acid of SO2 is:
a)
b)
c)
d) None

92) Baking soda is:
a) A basic salt
b) A double salt
c) A complex salt
d) An acidic salt

93) Which species does not act as an Lewis acid ?
a)
b)
c)
d)

94) Which statement is not correct in the case of a base ?
a) It acts as an electron pair donor
b) It accepts a proton
c) It turns blue litmus red
d) None

95) Which statement is correct ?
a)
b)
c)
d)

96) The hydrolysis of the oxide ion in water produces
a)
b)
c)
d)

97) Which one of the following is a Bronsted acid ?
a)
b)
c)
d)

98) Which is a Bronsted acid and a base?
a)
b)
c) CH3COO
d)

99) Which is not a Lewis acid?
a)
b)
c) BeCl4
d)

100) Which species does not act as an Bronsted acid ?
a)
b)
c)
d)


Answer :

Leave a Reply

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