A solution of sodium sulphate in water is electrolysed using inert electrodes. The products at the cathode and anode are respectively:

1. H₂, O₂

2. O₂, H₂

3. O₂, Na

4. O₂, SO₂

If the E°_cell for a given reaction has a negative value, which of the following gives correct relationships for the values of $∆$G° and K_eq ?

(1) $∆$G° >0;  K_eq< 1

(2) $∆$G° >0; K_eq>1

(3) $∆$G° < 0; K_eq> 1

(4) $∆$G° <0; K_eq< 1

A device that converts energy of the combustion of fuels like hydrogen and methane, directly

into electrical energy is known as:

1. Fuel cell

2. Electrolytic cell

3. Dynamo

4. Ni-Cd cell

A button cell used in watches functions as following

Zn(s) + Ag₂O(s) + H₂O (l) $\rightleftharpoons$2Ag(s) + Zn²⁺(aq) + 2OH^-(aq)

If half cell potentials are
\(\mathrm{Zn}^{2+}{ }_{\mathrm{aq}}+2 \mathrm{e}^{-} \rightarrow \mathrm{Zn}_{\mathrm{x}} ; \mathrm{E}^{\circ}=-0.76 \mathrm{~V}\)${{}^{}}_{}$

\(\mathrm{Ag}_2 \mathrm{O}{\mathrm{(s)}}+\mathrm{H}_2 \mathrm{O}(l)+2 \mathrm{e}^{-} \rightarrow 2 \mathrm{Ag}{\mathrm{(s)}}+2 \mathrm{OH}_{\mathrm{aq}}^{-} ; \mathrm{E}^{\circ}=0.34 \mathrm{~V}\)

The cell potential will be :

1. 0.84 V

2. 1.34 V

3. 1.10 V

4. 0.42 V

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.