The catalyst preferred in Haber's process is:

1. Finely divided iron
2. Graphite
3. Vanadium pentoxide
4. Platinum

The gas evolved when concentrated sulphuric acid reacts with zinc

1. Sulphur dioxide
2. Carbon dioxide
3. Hydrogen sulphide
4. Hydrogen

Assertion (A): The process of electrolysis is a redox reaction.

Reason (R): Reduction occurs at anode and oxidation at cathode.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

A hydrocarbon with double bond is:

1. Acetylene
2. Ethylene
3. Ethane
4. Methane