GCES chemistry unit 1 - saturated and unsaturated fats/oils

Saturated and unsaturated fats(solid) and oils(liquid)

Saturated

• Solid at room temperature
• Higher melting point
• Come from animals (e.g butter)
• Less healthy (build up cholesterol)
• NEVER HAS A DOUBLE BOND
• E.g alkane

Unsaturated

• Liquids at room temperature
• Lower melting point (due to double bond)
• From plants (e.g olive oil)
• More healthy
• ALWAYS HAS ONE OR MORE DOUBLE BONDS
• E.g alkene

Test for unsaturated fats

In bromine water, an unsaturated fat will turn the bromine water colourless and if it's a saturated fat, the solution will stay browny, orange.

Turning an unsaturated fat into an almost saturated fat

React the unsaturated fat (containing hydrocarbon chains) with hydrogen at 60 degrees. The double bonds break as the hydrogens join the hydrocarbons. 

Add a nickel catalyst to speed up the reaction.

It creates an almost saturated molecule

DOSEN'T GET RID OF ALL THE DOUBLE BONDS BUT MOST OF THEM (it's still healthier than fully saturated)

This almost saturated product can be turned into low fat butters as they now have a higher boiling point so are solid at room temperature. They are also great for making cakes. They are a healthier than fully-saturated products.