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41) X ampere current is passed for y seconds through copper and silver
voltameters. The metal that is deposited more is:
a) Ag
b) Na
c) Cu
d) Al
ANSWER : Ag
42) A current of 2 ampere was passed through solutions of CuSO4 and
AgNO3. The weight of copper deposited is 0.636 g. What is the weight
of silver deposited?
a) 3.16g
b) 4.32g
c) 2.61g
d) 2.16g
ANSWER : 2.16g
43) Na+ and K+ element have:
a) tendency to gain electrons.
b) positive reduction potential.
c) negative reduction potential.
d) negative oxidation potential.
ANSWER : negative reduction potential.
44) Ca and Cu metals when coupled together gives maximum emf for a voltaic
cell because:
a) It shows greater difference in standard reduction potential values.
b) It shows less difference in standard reduction potential value.
c) It shows same standard reduction potential value.
d) None of these.
ANSWER : It shows greater difference in standard reduction potential values.
45) A certain quantity of electricity was passed through CuSO4 solution
for 6 minutes 20 sec. The amount of Cu deposited is 0.317g. (At.wt.of Cuis 63.5
and Faraday = 96500 coulombs). Find the amount of electricity consumed in
ampere?
a) 25.
4 b) 27.3
c) 2.54
d) 2.73
ANSWER : 2.54
46) Find the number of electrons passing per second through a cross-section
of copper wire carrying 10A of current. < /P > a) 2.6 x 1019
b) 6 x 1019
c) 6 x 10-19
d) 2.6 x 10-19
ANSWER : 6 x 1019
47) In high energy density batteries Lithium is used as an electrode
because:
a) it is reactive.
b) it does not corrode easily.
c) it has high negative reduction potential.
d) it is the lightest metal.
ANSWER : it has high negative reduction potential.
48) 1 C contains ……………… number of electrons.
a) 6.24 x 1018
b) 6.03 x 1016
c) 6.05 x 1021
d) 6.24 x 1017
ANSWER : 6.24 x 1018
49) What is the correct efficiency, if an electricity of 10800C decomposes
14.25 gm of AgNO3?
a) 100%
b) 50%
c) 25%
d) 75%
ANSWER : 75%
50) Calculate the time required for a current of 2.5 A to obtain 1% coating
of Ag on a tea-pot weighing 0.27 Kg.
a) 965 sec
b) 40 sec
c) 1930 sec
d) 486 sec.
ANSWER : 965 sec .
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