Question

The gas used in the manufacture of vanaspati from vegetable oil is:

• A. Hydrogen
• B. Oxygen
• C. Nitrogen
• D. Carbon dioxide

Hint:

Vanaspati is solid fat made from liquid oil by adding a gas across double bonds.

Answer 1

The Correct Option is A

Step 1: Vanaspati is made from liquid vegetable oils, such as groundnut oil or cottonseed oil, by a process called hydrogenation.

Step 2: In hydrogenation, hydrogen gas is passed through the hot vegetable oil in the presence of a nickel catalyst. Hydrogen adds across the carbon-carbon double bonds \(C=C\) present in the unsaturated fatty acid chains of the oil.

Step 3: This addition converts the unsaturated liquid oil into a saturated solid or semi-solid fat, which is vanaspati, also called vanaspati ghee.

Step 4: Oxygen would oxidise the oil and spoil it. Nitrogen and carbon dioxide are inert here and do not react with the double bonds. Only hydrogen carries out this addition reaction.

Answer: Hydrogen, option A.