C6g Natural Fats and Oils Key Points

The main things to take away for oils and fats (Unit C6g) are as follows:

• Saturated means it contains only single bonds
• Unsaturated means it contains at least one double bond
• Animal Fats are often saturated
• Unsaturated fats and oils often come from vegetables and plants - they are better for you as saturated fats may lead to heart disease.

The test for unsaturation is that if you add yellow bromine water to to the oil it will go colourless if it is unsaturated.  It will stay yellow if it is saturated.

Making Margerine We can make margerine by adding hydrogen to an unsaturated oil (in the presence of a catalyst). This turns the oil into a soft solid as it becomes more saturated.

Oil and water do not mix. But is you add a stabiliser to the mixture you can get droplets of oil suspended in the water - this is called an emulsion

Making Soap -  This is called Sapononification. You heat the oils with sodium hydroxide:

                                  Fat +  Sodium Hydroxide --> Soap + Glycerol

The addition of the hydroxide make this a hydrolysis reaction