141. The number of electrons delivered at the cathode during electrolysis by a current of $${\text{1 ampere}}$$  in 60 seconds is ( charge on electron $${\text{ = 1}}{\text{.60}} \times {\text{1}}{{\text{0}}^{ - 19}}C$$     )

A $$6 \times {10^{23}}$$
B $$6 \times {10^{20}}$$
C $$3.75 \times {10^{20}}$$
D $$7.48 \times {10^{23}}$$
Answer :   $$3.75 \times {10^{20}}$$
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142. A graph was plotted between molar conductivity of various electrolytes $$\left( {NaCl,HCl\,{\text{and}}\,{\text{N}}{{\text{H}}_4}OH} \right)$$     and $$\sqrt c \left( {{\text{in}}\,mol\,{L^{ - 1}}} \right).$$     Correct set is :
Electrochemistry mcq question image

A $$I\left( {NaCl} \right),II\left( {HCl} \right),III\left( {N{H_4}OH} \right)$$
B $$I\left( {HCl} \right),II\left( {NaCl} \right),III\left( {N{H_4}OH} \right)$$
C $$I\left( {N{H_4}OH} \right),II\left( {NaCl} \right),III\left( {HCl} \right)$$
D $$I\left( {N{H_4}OH} \right),II\left( {HCl} \right),III\left( {NaCl} \right)$$
Answer :   $$I\left( {HCl} \right),II\left( {NaCl} \right),III\left( {N{H_4}OH} \right)$$
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143. The standard reduction potentials at $${25^ \circ }C$$  of $$\frac{{L{i^ + }}}{{Li}},\frac{{B{a^{2 + }}}}{{Ba}},\frac{{N{a^ + }}}{{Na}}$$    and $$\frac{{M{g^{2 + }}}}{{Mg}}$$  are – 3.03, – 2.73, – 2.71 and – 2.37 $$volt$$  respectively. Which one of the following is the strongest oxidising agent?

A $$N{a^ + }$$
B $$L{i^ + }$$
C $$B{a^{2 + }}$$
D $$M{g^{2 + }}$$
Answer :   $$M{g^{2 + }}$$
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144. Electrolysis of dilute aqueous $$NaCl$$  solution was carried out by passing 10 milli ampere current. The time required to liberate 0.01 mol of $${H_2}$$  gas at the cathode is $$\left( {1\,{\text{Faraday}} = 96500\,C\,mo{l^{ - 1}}} \right)$$

A 9.65 × 104 sec
B 19.3 × 104 sec
C 28.95 × 104 sec
D 38.6 × 104 sec
Answer :   19.3 × 104 sec
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145. Given : $${E^o}_{\frac{{F{e^{3 + }}}}{{Fe}}} = - 0.036V,$$     $${E^o}_{\frac{{F{e^{2 + }}}}{{Fe}}} = - 0.439\,V.$$     The value of standard electrode potential for the change, $$F{e^{3 + }}\left( {aq} \right) + {e^ - } \to F{e^{2 + }}\left( {aq} \right)$$      will be :

A $$0385 V$$
B $$0.770 V$$
C $$ - 0.270 V$$
D $$- 0.072 V$$
Answer :   $$0.770 V$$
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146. Units of the properties measured are given below. Which of the properties has not been matched correctly?

A Molar conductance $$ = S\,{m^2}\,mo{l^{ - 1}}$$
B Cell constant $$ = {m^{ - 1}}$$
C Specific conductance $$ = S\,{m^2}$$
D Equivalent conductance $$ = S\,{m^2}\,e{q^{ - 1}}$$
Answer :   Specific conductance $$ = S\,{m^2}$$
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147. Limiting molar conductivity for some ions is given below $$\left( {{\text{in}}\,S\,c{m^2}\,mo{l^{ - 1}}} \right):$$
$$N{a^ + } - 50.1,C{l^ - } - 76.3,$$     $${H^ + } - 349.6,C{H_3}CO{O^ - } - 40.9,$$       $$C{a^{2 + }} - 119.0.$$
What will be the limiting molar conductivities $$\left( { \wedge _m^ \circ } \right)$$  of $$CaC{l_2},C{H_3}COONa$$     and $$NaCl$$  respectively?

A $$97.65,111.0\,\,{\text{and}}\,\,{\text{242}}{\text{.8}}\,S\,c{m^2}\,mo{l^{ - 1}}$$
B $$195.3,182.0\,\,{\text{and}}\,\,26.2\,S\,c{m^2}\,mo{l^{ - 1}}$$
C $$271.6,91.0\,\,{\text{and}}\,\,126.4\,S\,c{m^2}\,mo{l^{ - 1}}$$
D $$119.0,1024.5\,\,{\text{and}}\,\,9.2\,S\,c{m^2}\,mo{l^{ - 1}}$$
Answer :   $$271.6,91.0\,\,{\text{and}}\,\,126.4\,S\,c{m^2}\,mo{l^{ - 1}}$$
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148. The amount of chlorine evolved by passing $$2\,A$$  of current in an aqueous solution of $$NaCl$$  for 30 minutes is

A 2.64 $$g$$
B 1.32 $$g$$
C 3.62 $$g$$
D 4.22 $$g$$
Answer :   1.32 $$g$$
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149. Fluorine is the best oxidising agent because it has

A highest electron affinity
B highest reduction potential
C highest oxidation potential
D lowest electron affinity
Answer :   highest reduction potential
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150. Galvanization is applying a coating of :

A $$Cu$$
B $$Zn$$
C $$Pb$$
D $$Cr$$
Answer :   $$Zn$$
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