On the basis of the information available from the reaction:

$\frac{4}{3}\mathrm{Al}+{\mathrm{O}}_2\to \frac{2}{3}{\mathrm{Al}}_2{\mathrm{O}}_3,$ $∆\mathrm{G}=-827$ $\mathrm{KJ}$ ${\mathrm{mol}}^{-1}$

The minimum e.m.f. required to carry out the electrolysis of Al₂O₃ is:
(F = 96500 C mol^–1)

1. 2.14 V

2. 4.28 V

3. 6.42 V

4. 8.56 V

The EMF of a Daniel cell at 298 K is E₁  Zn|ZnSO₄(0.01 M) || CuSO₄(1.0 M)|Cu.
When the concentration of ZnSO₄ is 1.0 M and that of CuSO₄ is 0.01 M, the EMF is changed to E₂. The correct relationship between E₁ and E₂ is:

In the silver plating of copper, K[Ag(CN)₂] is used instead of AgNO₃. The reason is:
 

In electrolysis of NaCl when Pt electrode is taken then H₂ is liberated at the cathode while with Hg cathode it forms sodium amalgam because:

The standard Emf of a galvanic cell involving cell reaction with n = 2 is found to be 0.295 V at 25 ºC. The equilibrium constant of the reaction would be:

(Given F = 96500 C mol^–1; R = 8.314 J K^–1 mol^–1) 

1. 4.0 × 10¹²

2. 1.0 × 10²

3. 1.0 × 10¹⁰

4. 2.0 × 10¹¹

The value of E⁰ cell for the following reaction is:
\(Cu^{2+}+ Sn^{2+}\to Cu +Sn^{4+ } \)

(Given, equilibrium constant is 10⁶)

At infinite dilution, equivalent conductances of Ba⁺² & Cl^– ions are 127 & 76 ohm^–1cm^–1 eq^–1 respectively. Equivalent conductance (ohm^–1cm^–1 eq^–1) of BaCl₂ at infinite dilution is:

1. 139.5

2. 101.5

3. 203

4. 279

A cell reaction become spontaneous when:

1. ∆Gº is negative

2. ∆Gº is positive

3. $E_{Red}^{°}$ is positive

4. $E_{Red}^{°}$ is negative

For the disproportionation of copper:

2Cu⁺ → C u²⁺ + C u$,$ $E°$ is:
(Given $E°$ for Cu⁺²/Cu is 0.34 V & Eº for Cu⁺²/Cu⁺ is 0.15 V )

1. 0.49 V

2. – 0.19 V

3. 0.38 V

4. – 0.38 V

4.5 g of aluminium (at. mass = 27 amu) is deposited at cathode from Al³⁺ solution by a certain quantity of electric charge. The volume of hydrogen produced at STP from H⁺ ions in solution by the same quantity of electric charge will be: