Concept:Hydrogenation of unsaturated oils uses a catalyst to add hydrogen and convert liquid oils into solid fats.Explanation:Unsaturated vegetable oils are liquid at room temperature.They are hardened by reacting with hydrogen gas in the presence of a catalyst.Nickel (Ni) is the common catalyst used for this reaction at about 60°C.Hydrogen adds to the carbon-carbon double bonds, making the oil more saturated and solid.
