Electro Chemistry (Advanced) - Practice Sheet, Class 12, Chemistry - JEE PDF Download

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LEARNERS HABITAT
1] During the electrolysis of cryolite, Aluminium and Fluorine are formed in the molar
ratio of
a) 3: 1 b) 1: 3 c) 2: 3 d) 3: 2
2] During the electrolysis of an aqueous salt solution, the pH in the space near one of the
electrode was increased and the other one was decreased. The salt solution was:
a) Cu (NO3)2 b) ZnCl2 c) NaClconc. d) NaCl very dilute
3] The density of copper is 8gm/cc. Number of coulombs required to plate an area of 10
cm x 10 cm on both sides to a thickness of 10
-2
 cm using CuSO
4
 solution as electrolyte is
a) 48,250 b) 24,125 c) 96,500 d) 10,000
4] Silver is removed electrolytically from 200 ml 0.1M solution of AgNO
3
 by a current of
0.1 amp. The time required to remove half the silver from the solution is seconds
a) 96,500 b) 9, 650 c) 965 d) 4, 825
5] When 965 amp current is passed through aqueous solution of salt X using platinum
electrodes for 10 sec, the volume of gasses liberated at the respective electrodes is in 1: 1
ratio. Then X is
a) MgSO
4
b) AgCl c) MgCl
2
d) KNO
3
6] The potential at which a solution containing 1 M CuSO
4
, 1 M NiSO
4
 and 2M H
2
SO
4
 be
electrolysed so as to deposit only copper and no nickel so that 1× 10
–9
 M Cu
2+
 is left, is
a) 0.04 V b) 0.4 V c) 0.07 V d) 0.007 V
7] The amount of energy spend during the passage of 1 ampere current for 100 sec under a
potential of 115 V:
a) 20 k J b) 11.5 kJ c) 115 kJ d) 0.115 kJ
8] In an experiment 0.04 F was passed through 400 ml of 1M solution of NaCl. What
would be the pH of the solution after the electrolysis ?
a) 8 b) 10 c) 13 d) 6
9] 9.65 C electric current is passed through fused anhydrous magnesium chloride. The
magnesium metal thus obtained is completely converted into a Grignard reagent. The
number of moles of the Grignard reagent obtained is
a) 5 x 10
-4
b) 1 x 10
-4 
c) 5 x 10
-5
d) 1 x 10
-5
LH Practice Sheet ELECTRO CHEMISTRY
LEARNERS HABITAT, 97/1, 3rd Floor, Near NCERT Gate No. 01, Adchini, New Delhi. +91-8510800081/82 
www.learnershabitat.ac.in Page 1
Page 2


LEARNERS HABITAT
1] During the electrolysis of cryolite, Aluminium and Fluorine are formed in the molar
ratio of
a) 3: 1 b) 1: 3 c) 2: 3 d) 3: 2
2] During the electrolysis of an aqueous salt solution, the pH in the space near one of the
electrode was increased and the other one was decreased. The salt solution was:
a) Cu (NO3)2 b) ZnCl2 c) NaClconc. d) NaCl very dilute
3] The density of copper is 8gm/cc. Number of coulombs required to plate an area of 10
cm x 10 cm on both sides to a thickness of 10
-2
 cm using CuSO
4
 solution as electrolyte is
a) 48,250 b) 24,125 c) 96,500 d) 10,000
4] Silver is removed electrolytically from 200 ml 0.1M solution of AgNO
3
 by a current of
0.1 amp. The time required to remove half the silver from the solution is seconds
a) 96,500 b) 9, 650 c) 965 d) 4, 825
5] When 965 amp current is passed through aqueous solution of salt X using platinum
electrodes for 10 sec, the volume of gasses liberated at the respective electrodes is in 1: 1
ratio. Then X is
a) MgSO
4
b) AgCl c) MgCl
2
d) KNO
3
6] The potential at which a solution containing 1 M CuSO
4
, 1 M NiSO
4
 and 2M H
2
SO
4
 be
electrolysed so as to deposit only copper and no nickel so that 1× 10
–9
 M Cu
2+
 is left, is
a) 0.04 V b) 0.4 V c) 0.07 V d) 0.007 V
7] The amount of energy spend during the passage of 1 ampere current for 100 sec under a
potential of 115 V:
a) 20 k J b) 11.5 kJ c) 115 kJ d) 0.115 kJ
8] In an experiment 0.04 F was passed through 400 ml of 1M solution of NaCl. What
would be the pH of the solution after the electrolysis ?
a) 8 b) 10 c) 13 d) 6
9] 9.65 C electric current is passed through fused anhydrous magnesium chloride. The
magnesium metal thus obtained is completely converted into a Grignard reagent. The
number of moles of the Grignard reagent obtained is
a) 5 x 10
-4
b) 1 x 10
-4 
c) 5 x 10
-5
d) 1 x 10
-5
LH Practice Sheet ELECTRO CHEMISTRY
LEARNERS HABITAT, 97/1, 3rd Floor, Near NCERT Gate No. 01, Adchini, New Delhi. +91-8510800081/82 
www.learnershabitat.ac.in Page 1
10] A current is passed through two cells connected in series. The first cell contains X
(NO3)3 (aq) and the second cell contains Y (NO3)2 (aq). The relative atomic masses of X
and Y are in the ratio 1 : 2. What is the ratio of the liberated mass of X to that of Y ?
a) 3 : 2 b) 1 : 2 c) 1 : 3 d) 3 : 1 e) 2 : 1
11] The resistance of a 0.10 M weak acid HA in a conductivity cell is 2.0 x 10
3
 ohm. The cell
constant of the cell is 0.78 cm
-1
 and ^0  of the acid is 390 S cm
2
 mol
-1
.
Consider the following statements :
1) pH of the acid solution = 3
2) pKa of the acid = 5
3) Degree of dissociation of the aicd = 0.01
Which of the statements given above are correct ?
a) 1 and 2 only b) 1 and 3 only c) 2 and 3 only d) 1, 2 and 3
12] Degree of dissociation of pure water is 1.9 x 10
-9
. Molar ionic conductances of H
+
 and
OH
-
 ions at infinite dilution are 200 S cm
2
 mol
-1
 and 350 S cm
2
mol
-1
 respectively. Molar
conductance of water is
a) 3.8 x 10
-7
 S cm2 mol
-1
b) 5.7 x 10
-7
 S cm2 mol
-1
c) 9.5 x 10
-7
 S cm2 mol
-1
d) 1.045 x 10
-7
 S cm2 mol
-1
13] Electrolyte KCl, KNO
3
 ,   HCl,    NaOAc,    NaCl ?
?
(S cm
2
mol
-1
]  149.9  145.0  426.2  91.0  126.5 
Calculate ?
?
HOAC 
using appropriate molar conductances of the electrolytes listed
above at infinite dilution in water at 25
0
C  
a) 390.7 b) 217.5 c) 517.2 d) 552.17
14] The potential of the cell containing two hydrogen electrodes as represented below
Pt, H
2
(g) | H
+
 (10
-6
M) || H
+
 (10
-4
M) |H
2
(g), Pt at 298K is
a) -0.118V b) -0.0591V c) 0.118V d) 0.0591V
15] E
o
cell
 of Zn/Zn
2+
 || Cu
2+
/Cu is 1.10 V at 25
o
C. The equilibrium constant for the
reaction Zn + Cu
2+
 ? Zn
2+
 +Cu
a) 10
–28
b) 10
+37
c) 10
–18
d) 10
17
LH Practice Sheet ELECTRO CHEMISTRY
LEARNERS HABITAT, 97/1, 3rd Floor, Near NCERT Gate No. 01, Adchini, New Delhi. +91-8510800081/82 
www.learnershabitat.ac.in
 
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