How many columbs of electricity are consumed when 100 mA current is passed through a solution of AgNO₃ for 30 minute during an electrolysis experiment?

(1) 108

(2) 18000

(3) 180

(4) 3000

Standard reduction potentials at 25$°$C of Li⁺/Li, Ba²⁺/Ba, Na⁺/Na and Mg²⁺/Mg are -3.05, -2.90, -2.71 and -2.37 V respectively. Which one of the following is the strongest oxidising agent ?

(1) Mg²⁺

(2) Ba²⁺

(3) Na⁺

(4) Li⁺

For the cell, Ti/Ti⁺(0.001M)||Cu²⁺(0.1M)|Cu, ${\mathrm{E}}_{\mathrm{cell}}^{\mathrm{o}}$ $$at

25 $°$C is 0.83 V. E_cell can be increased :

1. By increasing [Cu²⁺]

2. By increasing [Ti⁺]

3. By decreasing [Cu²⁺]

4. None of the above.

A hydrogen gas electrode is made by dipping platinum wire in a solution of HCI of pH = 10 and by passing hydrogen gas around the platinum wire at 1 atm pressure. The oxidation potential of electrode would be

1. 0.059 V

2. 0.59 V

3. 00.118 V

4. 1.18 V

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