A depolariser used in dry cell batteries is: 

1. Ammonium chloride 

2. Manganese dioxide

3. Potassium hydroxide 

4. Sodium phosphate

The reaction taking place  at anode when an aqueous solution of CuSO₄ is electrolysed using inert Pt electrode:

1. 2${\mathrm{SO}}_4^{2-}$ $\to$ S₂${\mathrm{O}}_3^{2-}$ + 2e

2. Cu²⁺ + 2e $\to$Cu

3. 2H₂O $\to$ O₂ + 4H⁺ + 4e

4. 2H⁺ +2e $\to$ H₂

An increase in equivalent conductance of a strong electrolyte with dilution is mainly due to

1. increase in ionic mobility of ions

2. 100% ionisation of electrolyte at normal dilution

3. increase in both, i.e. number of ions and ionic mobility of ions

4. increase in number of ions

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 the electrode would be:

1. 0.059 V
2. 0.59 V
3. 00.118 V
4. 1.18 V

4.5 g of aluminium (atomic mass 27u) 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

1. 44.8 L

2. 22.4 L

3. 11.2 L

4. 5.6 L

Which one of the following pairs of substances on reaction will not evolve H₂ gas?

1. Iron and H₂SO₄ (aq)

2. iron and steam

3. Copper and HCl(aq)

4. Sodium and ethyl alcohol

A certain current liberates 0.504 g of hydrogen in 2 hr. How many gram of copper can be liberated by the same current flowing for the same time in CuSO₄ solution?

1. 12.7

2. 16

3. 31.8

4. 63.5

For the reductidon of silver ions with copper metal, the standard  cell potential was found to be + 0.46 V at 25⁰C. 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.