The temperature coefficient of a standard Cd–cell is –5.0 $\times$ 10^–5 Vk^–1 whose emf at 25°C is 1.018 V. During the cell operation, the temperature will –

(1) increase

(2) decrease

(3) either

(4) remains constant

A cell Ag | Ag⁺ || Cu⁺⁺ | Cu initially contains 2M Ag⁺ and 2M Cu⁺⁺ ions. The charger in cell potential after the passage of 10 amp current for 4825 sec is:

(1) –0.000738 V

(2) –1.00738

(3) –0.0038 V

(4) none

For the cell (at 298 K)

Ag(s) | AgCl(s) | Cl^–(aq) || AgNO₃(aq) | Ag(s)

Which of the following is correct –

(1) The cell emf will be zero when [Ag⁺]_a = [Ag⁺]_c ([Ag⁺] in anodic compartment = [Ag⁺] in cathodic compartment)

(2) The amount of AgCl(s) precipitate in anodic compartment will decrease with the working of the cell.

(3) The concentration of [Ag⁺] = constant, in anodic compartment during working of cell.

(4) E_cell = E°_{Ag+ | Ag} –E°_{Cl–|AgCl|Ag} $\text{−}\frac{0.059}{1}\log \frac{1}{{\left[{\mathrm{Cl}}^{-}\right]}_{\mathrm{a}}}$

During electrolysis of conc. H₂SO₄, perdisulphuric acid (H₂S₂O₈), and O₂ form in equimolar amount. The amount of H₂ that will form simultaneously will be : 

1. Thrice that of O₂ in moles.

2. Twice that of O₂ in moles.

3. Equal to that of O₂ in moles.

4. Half of that of O₂ in moles.

In producing chlorine by electrolysis 100 kW power at 125V is being consumed.How much chlorine per minute is liberated (ECE of chlorine is 0.367$\times {10}^{-6}kg{C}^{-1}$)

(1) $1.76\times {10}^{-3}kg$                                   

(2) $9.67\times {10}^{-3}kg$

(3) $17.61\times {10}^{-3}kg$                                 

(4) $3.67\times {10}^{-3}kg$ 

Select the correct statement if –

E°_Mg²⁺/Mg = –2.4V, E°_{Sn⁴⁺/Sn²⁺} = 0.1 V, \(E_{MnO_{4}^{-}\, ,H^{+}\,/\,Mn^{+2} }^{\circ}\) = 1.5 V, \(E_{I_{2}\,/\,I^{-}}^{\circ} \)= 0.5 V

Here,

Which of these ions Cu⁺, Co³⁺, Fe²⁺ is stable in aqueous medium.

Given :E°_Cu2+/Cu+ = 0.15 volt ; E°_Cu+/Cu = 0.53 V ;E°_Co3+/Co2+ = 1.82 V ;

E°_Fe3+/Fe2+ = 0.77 V ;E°_Fe2+Fe = –0.44 V ;E°_O2,H+/H2O = 1.23 V

(1) Cu⁺, Co³⁺

(2) Co³⁺

(3) Cu⁺

(4) Co³⁺, Cu⁺, Fe²⁺

Calculate the useful work of the reaction Ag(s) + 1/2Cl₂(g) $\underset{}{\overset{}{\to }}$ AgCl(s)

Given $\mathrm{E}{°}_{\mathrm{Cl}2/{\mathrm{Cl}}^{–}} = + 1.36 \mathrm{V}, \mathrm{E}{°}_{\mathrm{AgCl}/\mathrm{Ag},{\mathrm{Cl}}^{–}} = 0.22 \mathrm{V}$

If ${\mathrm{P}}_{{\mathrm{Cl}}_2}$ = 1 atmand T = 298 K

(1) 110 kJ/mol

(2) 220 kJ/mol

(3) 55kJ/mol

(4) 1000 kJ/mol

Consider the cell Ag(s)|AgBr(s)|Br–(aq)||AgCl(s)|Cl–(aq)|Ag(s) at 25°C. The solubility product constants of AgBr & AgCl are respectively 5 × 10^–13 & 1 × 10^–10. For what ratio of the concentrations of Br^– & Cl^–ions would the emf of the cell be zero ?

(1) 1 : 200

(2) 1 : 100

(3) 1 : 500

(4) 200 : 1

Acetic acid has K_a = 1.8 × 10^–5 while formic acid had K_a = 2.1 × 10^–4. What would be the magnitude of the emf of the cell

Pt(H₂) $\left|\begin{array}{l}0.1\mathrm{M} \mathrm{acetic} \mathrm{acid}+\\ 0.1\mathrm{M} \mathrm{sodium} \mathrm{acetate}\end{array}\right|\left|\begin{array}{l}0.1\mathrm{M} \mathrm{formic} \mathrm{acid}+\\ 0.1\mathrm{M} \mathrm{sodium} \mathrm{formate}\end{array}\right|$ Pt(H₂) at 25°C

(1) 0.0315 volt

(2) 0.0629 volt

(3) 0.0455 volt

(4) 0.0545 volt