$2{\stackrel{\oplus }{\mathrm{Ag}}}_{\left(\mathrm{aq}\right)} + {\mathrm{Cu}}_{\left(\mathrm{s}\right)} \stackrel{ }{\rightleftharpoons } {{\mathrm{Cu}}_{\left(\mathrm{aq}\right)}}^{+2} + 2{\mathrm{Ag}}_{\left(\mathrm{s}\right)}$

The cell potential for this reaction is 0.46V. Which of the following change will increase the potential the most ?

(1) $\left[\stackrel{\oplus }{\mathrm{Ag}}\right]$ concentration is doubled

(2) [Cu²⁺] concentration is halved

(3) Size of Cu_(s) electrode is doubled

(4) size of Ag_(s) electrode is decreased to half

What will be the value of $∆\mathrm{G}°$ for the rection ${\mathrm{Cu}}^{+2} + \mathrm{Fe} \stackrel{ }{\rightleftharpoons } {\mathrm{Fe}}^{+2} + \mathrm{Cu} ,$

if ${\mathrm{E}}_{\raisebox{1ex}{${\mathrm{Cu}}^{+2}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{Cu}$}\right.}^{\circ } = +0.34 \mathrm{V} \mathrm{and} {\mathrm{E}}_{\raisebox{1ex}{${\mathrm{Fe}}^{+2}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{Fe}$}\right.}^{\circ } = -0.44 \mathrm{V}$$$

(1) -65.62 KJ

(2) -75.27 KJ

(3) -150.54 KJ

(4) +150.54 KJ

At 298 K the Emf of the following cell is:-

\(\small{Pt|H_{2}(1 \ atm)|H^{+}(0.02 \ M) \ || \ H^{+}(0.01 \ M)|H_{2}(1 \ atm)|Pt}\)

1. - 0.017 V

2. 0.0295 V

3. 0.1 V

4. 0.059 V

At 25$°$C temperature Zn electrode is placed in 0.1M solution of zinc salt then what will be the reduction potential ? If it is assumed that salt dissociates 25% at this dilution (${\mathrm{E}}_{\raisebox{1ex}{${\mathrm{Zn}}^{2+}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{Zn}$}\right.}^{°} = -0.76 \mathrm{V}$)

(1) -0.713 V

(2) - 0.81 V

(3) + 0.778 V

(4) - 0.84 V

The reduction potential of Hydrogen electrode is -118mV then the concentration of ${\mathrm{H}}^{\oplus }$ion in solution will be :-

(1) 10^-4M

(2) 2M

(3) 0.01M

(4) 10^-3M

The maximum work which can be obtained from a Daniel cell \(Zn_{(s)}\ |\ Zn^{+2}_{(aq)}\ || Cu^{+2}_{(aq)}\ |\ Cu_{(s)}\) is:

1. 106.15 kJ

2. -212.3 kJ

3. 424.6 kJ

4. +212.3 kJ

CuSO₄ solution is treated separately with KCl and KI. In which case, Cu⁺² will be reduced to ${\mathrm{Cu}}^{\oplus }$ ?

(1) with KCl

(2) with KI

(3) with KCl and KI both

(4) None of these

How many coulombs are required to oxidise 1 mol H₂O₂ to O₂ ?

(1) 9.65 X 10⁴ C

(2) 9.3 X 10⁴ C

(3) 1.93 X 10⁵ C

(4) 19.3 X 10² C

The quantity of electricity required to reduce 12.3 g of nitrobenzene to aniline with 50 % current efficiency is:

1. 1 F

2. 0.6 F

3. 0.5 F

4. 1.2 F

Electrolysis of hot aqueous solution of NaCl gives NaClO₄ as-

$\mathrm{NaCl} +\hspace{0.17em}4{\mathrm{H}}_2\mathrm{O} \stackrel{ }{\to }{\mathrm{NaClO}}_4 + 4{\mathrm{H}}_2$

How many faraday are required to obtain 1000 g of sodium perchlorate ?

(1) 66 F

(2) 122.5 F

(3) 15.13 F

(4) 1.86 F