Fats, Oils & Soaps

Fats, Oils & Soaps

1. Fats and oils = big ester molecules.

2. Made from alcohols and carboxylic acids.

3. Fats = solid and Oils = liquid at room temperature.

   • Fats have a higher melting point than room temperature.
   • Oils have a lower melting point than room temperature.

4. Fats = Saturated fats Oils = Unsaturated fats

5. Break double bonds by adding hydrogen = hydrogenation. This turns oil into a solid.

6. Soaps

   • Concentrated alkali + oil/fat = soap + glycerol
     • Sodium hydroxide + glyceryl tristearate = sodium stearate + glycerol
       • Sodium stearate is an example of a soap.
   • The soap molecule has two specific ends that behave differently.
     • Section 1 is a hydrophobic (water-hating/grease-loving)
     • Section 2 is ionic and hydrophilic (water-loving/grease-hating)
     • The hydrocarbon tail is hydrophobic and wants to get out of the water.
       • They bury their tail in the grease to get out of the water and the hydrophilic head is happy.
         • Once their is enough hydrocarbons to fill up the grease, the grease starts to move away from the skin so more can fit and there is more surface area.
           • Grease is separated from the skin.
   • Slightly alkaline.
     • The surface of our skin is covered in oils and these can react with the alkaline soap to for more soap and thus removes the oils and makes our skin feel 'dry'.
       • More expensive soaps contain 'moisturisers'.
       • pH balanced soaps are also available.

7. Oven Cleaners

   • Oven cleaners contain strong alkalis that react with the fats to form a soap. This can then be removed easily.