Unsaturated hydrocarbons add hydrogen in the presence of catalyst such as palladium or nickle to give saturated hydro carbons catalyst are subtances that cause a reaction to occur or proceed at a different rate without the reaction itself bieng affected this reaction is commonly known as hydrogenation of vegetable oil using nickle catalyst vegetable oils generally have long unsaturated carbon chains while animals fats have saturated carbon chains.
The reaction in which hydrogen is added to unsaturated hydrocarbon to make saturated hydrocarbons is called hydrogenation or addition reaction.

Adsition of hydrogen
Hydrogenation is the process in which hydrogen is added to unsaturated hydrocarbons to obtain a saturated hydrocarbon
Hyrodro

No of water molecule added

It is process of addition of hrdrogen.
The addition of hydrogen to an unsaturated hydrocarbon to obtain a saturated hydrocarbon is called hydrogenation
Addition of hydrogen gas
Passing of hydrogen gas through vegetable oil to convet it to ghee…

E.g. vegitative oil to form ghee
Conversation of unsaturated hydrocarbons into Saturated hydrocarbon is known as hydrogenation