Pairs of reactants (R) and product (P) are given below. The pair which can be used in a fuel cell is :

1. $R\mathit{=}{H}_{\mathit{2}\mathit{\left(}\mathit{g}\mathit{\right)}}\mathit{,}{O}_{\mathit{2}\mathit{\left(}\mathit{g}\mathit{\right)}}\mathit{;}P\mathit{=}{H}_{\mathit{2}}{O}_{\mathit{2}\mathit{\left(}\mathit{g}\mathit{\right)}}$

2. $\mathrm{R}={\mathrm{H}}_{2\left(\mathrm{g}\right)},{\mathrm{O}}_{2\left(\mathrm{g}\right)};\mathrm{P}={\mathrm{H}}_2{\mathrm{O}}_{\left(\mathrm{\ell }\right)}$

3. $\mathrm{R}={\mathrm{H}}_{2\left(\mathrm{g}\right)},{\mathrm{O}}_{2\left(\mathrm{g}\right)},{\mathrm{Cl}}_{2\left(\mathrm{g}\right)};\mathrm{P}={\mathrm{HClO}}_{4\left(\mathrm{aq}\right)}$

4. $\mathrm{R}={\mathrm{H}}_{2\left(\mathrm{g}\right)},{\mathrm{N}}_{2\left(\mathrm{g}\right)};\mathrm{P}={\mathrm{NH}}_{3\left(\mathrm{aq}\right)}$

The cell that will measure the standard electrode potential of a copper electrode is:

Which of the following statements is correct for the electrolysis of CuSO₄ solution?

1. Cathode reaction: Cu²⁺ + 2e^- $\to$ Cu using Cu electrode.

2. Anode reaction: Cu $\to$ Cu⁺ + e^- using Cu electrode.

3. Cathode reaction: 2H⁺ + 2e^- $\to$H₂ using Pt electrode.

4. Anode reaction: Cu $\to$ Cu²⁺ + 2e^- using Pt electrode.

The half-cell reaction at the anode during the electrolysis of aqueous sodium chloride solution  is represented by : 

1. Na⁺(aq) + e^- ⟶ Na(s) ; \(E_{cell}^{o} \ = \ -2.71 \ V \)

2. 2H₂O(l) ⟶ O₂(g) + 4H⁺(aq) + 4e^- ; \(E_{cell}^{o} \) = 1.23 V

3. H⁺(aq) + e^- ⟶ \(\frac{1}{2}\)H₂(g) ; \(E_{cell}^{o} \) = 0.00 V

4. Cl^-(aq) ⟶ \(\frac{1}{2}\)Cl₂(g) + e^- ; \(E_{cell}^{o}\) \(= 1 . 36  V\)

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.

On electrolysis of dilute sulphuric acid using Platinum (Pt) electrode, the product obtained at the anode will be:

1. Oxygen gas

2. ${\mathrm{H}}_2\mathrm{S}$ gas

3. ${\mathrm{SO}}_2$ gas

4. Hydrogen gas 

An electrochemical cell behaves as an electrolytic cell when the externally applied potential (Eext)
becomes greater than the cell potential (Ecell). Which of the following conditions is correct?

1. E_cell = 0

2. E_cell > E_ext

3. E_ext > E_cell

4. E_cell = E_ext

The correct statement about the given galvanic cell equation is:

Zn_(s) + 2Ag⁺­­­_(aq) → Zn²⁺_(aq) + 2Ag_(s)

When aqueous NaCl solution is electrolysed using inert electrodes then pH of the solution-

1. Increases.

2. Decreases.

3. Remains same.

4. First increases then decreases.

Salt with the highest electrolytic conductivity in solution is : 

1. K₂[PtCl₆] 

2. [Co(NH₃)₃(NO₂)₃]

3. K₄[Fe(CN)₆] 

4. [Co(NH₃)₄]SO₄