The atomic mass of Al is 27. When a current of 5 faraday is passed through a solution of Al³⁺ ions, the mass of Al deposited is:

(1) 27g

(2) 36g

(3) 45g

(4) 9g

On the basis of the information available from the reaction.

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

of O₂, the minimum EMF 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

For the reduction of silver ions with copper metal, the standard cell potential was found to be + 0.46 V at 25ºC. The value of standard Gibbs energy, $\Delta$G⁰ will be (F = 96500 Cmol^-1)

1. -89.0 KJ

2. 89.0 J

3. -44.5 KJ

4. -98.0 KJ

A solution of sodium sulphate in water is electrolysed using inert electrodes. The products at the cathode and anode are respectively:

(1) H₂, O₂

(2) O₂, H₂

(3) O₂, Na

(4) O₂, SO₂

If a salt bridge is removed from the two half cells, the voltage:

(1) drops to zero

(2) does not change

(3) increases gradually

(4) increases rapidly

Two electrolytic cells, one containing acidified ferrous chloride and another acidified ferric chloride are connected in series. The ratio of iron deposited at cathodes in the two cells when electricity is passed through the cells will be:

(1) 3:1

(2) 2:1

(3) 1:1

(4) 3:2

Pick out the incorrect statement

(1) Equivalent conductance increases with dilution

(2) Molar conductance increases with dilution

(3) Specific conductance increases with dilution

(4) Specific resistance increases with dilution

$2{\stackrel{\oplus }{\mathrm{Ag}}}_{\left(\mathrm{aq}\right)} + {\mathrm{Cu}}_{\left(\mathrm{s}\right)} \stackrel{ }{\rightleftharpoons } {{\mathrm{Cu}}_{\left(\mathrm{aq}\right)}}^{+2} + 2{\mathrm{Ag}}_{\left(\mathrm{s}\right)}$

The cell potential for this reaction is 0.46V. Which of the following change will increase the potential the most ?

(1) $\left[\stackrel{\oplus }{\mathrm{Ag}}\right]$ concentration is doubled

(2) [Cu²⁺] concentration is halved

(3) Size of Cu_(s) electrode is doubled

(4) size of Ag_(s) electrode is decreased to half

What will be the value of $∆\mathrm{G}°$ for the rection ${\mathrm{Cu}}^{+2} + \mathrm{Fe} \stackrel{ }{\rightleftharpoons } {\mathrm{Fe}}^{+2} + \mathrm{Cu} ,$

if ${\mathrm{E}}_{\raisebox{1ex}{${\mathrm{Cu}}^{+2}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{Cu}$}\right.}^{\circ } = +0.34 \mathrm{V} \mathrm{and} {\mathrm{E}}_{\raisebox{1ex}{${\mathrm{Fe}}^{+2}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{Fe}$}\right.}^{\circ } = -0.44 \mathrm{V}$$$

(1) -65.62 KJ

(2) -75.27 KJ

(3) -150.54 KJ

(4) +150.54 KJ

The cell reaction of micro electrochemical cell fromed during rusting of iron is:-