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21) Which is a secondary cell?
a) Mercury cell.
b) Dry cell.
c) H2 – O2 cell.
d) Ni – Cd cell.
ANSWER : Ni – Cd cell.
22) If the electrode potentials of both the electrodes become equal in
magnitude but opposite in sign then:
a) an electrochemical cell stops working.
b) an electrochemical cell starts working.
c) an electrochemical cell is reversed.
d) none of these.
ANSWER : an electrochemical cell stops working.
23) …………….. is the amount of electricity required to deposit 1 mol of
aluminium from a solution of AlCl3 .
a) Faraday
b) 1 ampere
c) 3 Faradays
d) 3 Ampere
ANSWER : 3 Faradays
24) If half cell reaction A + e- ? A- has large
negative reduction potential, it shows that:
a) A is readily reduced
b) A- is readily reduced.
c) A- is readily oxidized.
d) None of these.
ANSWER : A- is readily oxidized.
25) Four alkali metals K, L, M and N are having standard electrode
potentials as -4.05, -2.66, -0.50 and 0.70 V respectively. Which one of the
following is most reducing?
a) N
b) M
c) L
d) K
ANSWER : K
26) The oxidation potential of Mg and Al are +2.37 and +1.66 volt
respectively. The Mg in chemical reaction:
a) will not replace Al at all.
b) will replace Al.
c) will be replaced by Al
d) none of the above.
ANSWER : will replace Al.
27) An aqueous solution of Na2SO4 is electrolysed
using platinum electrodes. The products at the anode and the cathode are:
a) O2, Na
b) SO4-, H2
c) SO4-, Na
d) O2, H2
ANSWER : O2, H2
28) The conductivity of a saturated solution of Na2SO4
is 3.06 x 10-6 ohm-1. The Ksp for Na2SO4
will be (equivalent conductance = 1.53 ohm-1 equiv-1)
< P > a) 3.5 x 10-9
b) 2.5 x 10-14
c) 5 x 10-15
d) 4 x 10-6
ANSWER : 4 x 10-6
29) The standard reduction potentials of Zn2+ ¦ Zn and Zn2+
¦ Zn+ are 0.337 and 0.153 V respectively. The standard electrode
potential of Cu+ / Cu half cell is:
a) 0.184 V
b) 0.590 V
c) 0.727 V
d) 0.421 V
ANSWER : 0.184 V
30) A standard hydrogen electrode has zero electrode potential because:
a) hydrogen is the lightest element.
b) hydrogen is easiest to oxidize.
c) this electrode potential is assumed to be zero.
d) hydrogen has only one electron.
ANSWER : this electrode potential is assumed to be zero.
Part 1
Part 2 Part 3
Part 4
Part 5
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