The number of Faradays (F) required to produce 20 g of calcium from molten CaCl₂ (Atomic mass of Ca = 40 g mol^–1) is:

1. 2

2. 3

3. 4

4. 1

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 

In a typical fuel cell, the reactants (R) and products (P) are: 

Limiting molar conductivities, for the given solutions, are :

${\lambda }_m^0\left(H_{2}S{O}_4\right)=\hspace{0.17em}x$ $\mathrm{S }c{m}^2$ $mo{l}^{-1}$

${\lambda }_m^0\left(K_{2}S{O}_4\right)=\hspace{0.17em}y$ $\mathrm{S }c{m}^2$ $mo{l}^{-1}$

${\lambda }_m^0\left(C{H}_{3}COOK\right)=\hspace{0.17em}z$ $\mathrm{S }c{m}^2$ $mo{l}^{-1}$

From the data given above, it can be concluded that \(\lambda_m^0 \) in (\(S\ cm^2\ mol^{-1}\)) for CH₃COOH will be :
1. \(\mathrm{x-y+2z}\)       
2. \(\mathrm{x+y+z}\)          
3. \(\mathrm{x-y+z}\)       
4. \(\mathrm{{(x-y) \over 2}+z}\)          

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?

${10}^5$ coloumb charge liberated 1 gm silver (Ag). If the charge is doubled then the amount of liberated Ag will be:

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