Soap Making
****DISCLAIMER****
This experiment requires the use of a concentrated solution of a strong alkali (5M sodium hydroxide) and for this reason it should be very closely supervised. Eye protection, gloves and protective overalls should be worn. Under no circumstances should this experiment be carried out without suitable supervision.
Method
2cm3 of castor oil was placed in a 100ml beaker. To this 10cm3 of 5M sodium hydroxide was added. The mixture was then boiled for 5 minutes with constant stirring. 10cm3 of distilled water was then added and the mixture boiled for a further 3 minutes.
10g of sodium chloride was then added to the mixture and it was boiled for another 3 minutes. The mixture was allowed to cool.
A tablet of soap formed on the surface of the mixture. This was very carefully removed and dissolved in water.
The water produced a foam indicating that saponification of the oil had taken place.
NB the tablet of soap was still very alkaline and could not be used for washing without further treatment.