At $25°C$, the standard emf of cell having reactions involving two electron change is found to be 0.295 V. The equilibrium constant of the reaction is-

$\left(A\right) 29.5 \times {10}^{-2}$

$\left(B\right) 10$

$\left(C\right) {10}^{10}$

$\left(D\right) 29.5 \times {10}^{10}$

How much current is necessary to produce $H_2$ gas at the rate of 1 $c{m}^3$ per second under STP ?

(A) 4.305 amp                                           

(B) 17.22 amp

(C) 8.61 amp                                            

(D) 2.1525 amp.

During discharge of a lead storage cell, the density of sulphuric acid in the cell-

1. Increases.                                     

2. Decreases.

3. Remains unchanged.                      

4. Initially increases but decreases subsequently.

$F_2$ gas can’t be obtained by the electrolysis of any $F^{-1}$salt because-

(1) Fluorine is the strongest reducing agent

(2) Fluorine is the strongest oxidising agent.

(3) Fluorine easily combine with atmospheric $O_2$

(4) All

The metal that cannot be produced on reduction of its oxide by aluminium is :

(1) K                                                        

(2) Mn

(3) Cr                                                      

(4) Fe

The calomel electrode is reversible with respect to-

1. Mercury                                       

2. $H^{+}$

3. $H{g}^{2+}$                                          

4. $C{l}^{-}$

The standard oxidation potentials of $Cu/C{u}^{2+}$and $C{u}^{+} /C{u}^{2+} are – 0.34V and – 0.16 V$respectively. The standard electrode potential of $C{u}^{+} /Cu$ would be :

1. 0.18V  

2. 0.52V

3. 0.82V    

4. 0.49V

 ${\mathrm{E}}^0 \mathrm{for} \mathrm{the} \mathrm{reaction}$
$\mathrm{Fe} + {\mathrm{Zn}}^{2+} = \mathrm{Zn} + {\mathrm{Fe}}^{2+} \mathrm{is} – 0.35 \mathrm{V}.$
The   given   cell   reaction   is: 

1. Feasible  

2. Not feasible

3. In equilibrium 

4. None of the above

The  number of electrons involved in the deposition of 63.5 g of Cu from a solution of $CuS{O}_4$ is:

1 $6.022$ $\times$ ${10}^{23}$ $$

2 $3.011$ $\times$ ${10}^{23}$ $$

3 $12.044$ $\times$ ${10}^{23}$ $$

4 $$ $6.022$ $\times$ ${10}^{22}$

The reduction potential of a half-cell consisting of a Pt electrode immersed in $1.5 M F{e}^{2+}$and $0.015 M F{e}^{3+}$ solution at $25°C is \left(E_{\left(F{e}^{+3}, Fe+2\right)}^{°}=+0.770 v\right)$.

(1) 0.652 V                                                   

(2) 0.88 V

(3) 0.710 V                                                   

(4) 0.850 V