The Gibb's energy for the decomposition of \(\mathrm{A l_{2} O_{3}}\) at \(\mathrm{500~ ^\circ C}\) is as follows: 

2/3Al₂O₃ → 4/3Al + O₂ ; ∆_rG = + 960 k J mol^–1

The potential difference needed for the electrolytic reduction of aluminium oxide (Al₂O₃) at \(\mathrm{500~ ^\circ C}\) is at least,

1. 3.0 V 

2. 2.5 V 

3. 5.0 V 

4. 4.5 V 

Molar conductivities $(\wedge {°}_m)$ at infinite dilution of
NaCl, HCl, and $C{H}_{3}COONa$ are 126.4, 425.9, and 91.0 S cm² mol^–1 respectively.
 $(\wedge {°}_m)$  for $C{H}_{3}COOH$  will be: 

The correct expression that  represents the equivalent conductance at infinite dilution of $A{l}_2{\left(S{O}_4\right)}_3$ is:

(Given that ${\wedge }_{A{l}^{3+}}^{°}$ $and$ ${\wedge }_{S{O}_4^{2-}}^{°}$ are the equivalent conductances at infinite dilution of the respective ions)

1. ${\wedge }_{A{l}^{3+}}^{°}$ $+$ ${\wedge }_{S{O}_4^{2-}}^{°}$

2. $\left({\wedge }_{A{l}^{3+}}^{°}\right)$ $+$ ${\wedge }_{S{O}_4^{2-}}^{°}\times 6$

3. $\frac{1}{3}{\wedge }_{A{l}^{3+}}^{°}$ $+\frac{1}{2}$ ${\wedge }_{S{O}_4^{2-}}^{°}$

4. $2{\wedge }_{A{l}^{3+}}^{°}$ $+3$ ${\wedge }_{S{O}_4^{2-}}^{°}$

Consider the following relations for emf of an electrochemical cell:

Which of the following combinations correctly represents the relation for the emf of the cell?

The concentration of $ZnC{l}_2$ solution will change when it is placed in a container which is made of:

The cell reaction of an electrochemical cell is \(Cu^{2+}(C_{1}) + Zn \to Cu + Zn^{2+}(C_{2})\).

The change in free energy will be the function of:

\(1. \ ln (C_{1}+C_{2})\)
2. \(ln (\frac{C_{2}}{C_{1}})\)
\(3. \ ln C_{2}\)
\(4. \ lnC_{1}\)

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

A cell reaction become spontaneous when:

1. ∆Gº is negative

2. ∆Gº is positive

3. $E_{Red}^{°}$ is positive

4. $E_{Red}^{°}$ is negative

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

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

(Given, equilibrium constant is 10⁶)