CBSE Class 10 Answered

Unsaturated hydrocarbons are more reactive due to presence of double or triple bonds. They undergo addition reactions across the carbon-carbon double bonds to produce saturated hydrocarbons.

Addition of hydrogen across C-C double bonds is called hydrogenation. Unsaturated hydrocarbons add hydrogen in the presence of catalysts such as nickel/palladium to give saturated hydrocarbons.

For example:

Vegetable oils used for cooking are long unsaturated hydrocarbons which are healthy. Whereas animal fats such as vanaspati are saturated hydrocarbons and unhealthy for consumption. It can solidify and block the arteries of the heart.