Oils and fats

Fats and Oils are also hydrocarbons and some of the same definitions apply:

• fats have no C=C double bonds.
• Vegetable oil molecules with one double bond are called .
• Oil molecules with more than one double bond are called .

Polyunsaturated oils are far less viscous (more runny) than saturated ones, because double bonds are more than single bonds. This means they don't wrap around each other as much as the more bendy saturated chains.

The polyunsaturated oils from vegetables are more healthy than the lards and fats from animals. However they are not very good for spreading. To solidify them we need to turn them into saturated hydrocarbons. This can be done through . This is involves adding hydrogen in a similar way to bromine test.

Hydrogenation

The nickel acts as a , it speeds up the reaction with out being used up or changed. The nickel is filtered out and the saturated fat is used to make foods such as margarine, chocolate, penut butter, biscuits and cakes. It turns out that this also slows the products from going of.