A soap molecule. The grey, red, and white balls represent carbon, oxygen, and hydrogen atoms, respectively. The sodium ion near the negatively charged oxygen atoms is not shown.
The head is the sodium or potassium salt of an organic acid.
How do you make a molecule like this? Animal fat contains them, chemically bound to a small three-armed molecule called glycerol. The links between each of the three acid molecules and the glycerol are easily broken in a hot, alkaline solution:
|+ 3 NaOH||+|
|A glyceride (three fatty acids bound to a glycerol)||three soap molecules||glycerol|
|+ 3 NaOH||3 RCOO- Na+||+|
This reaction was used to make soap by treating animal fat with wood ash (which contain a high concentration of potassium hydroxide and potassium carbonate) long before the chemistry of the process was understood.
Author: Fred Senese email@example.com
Copyright © 1997-2010 by Fred Senese
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Last Revised 02/23/18.URL: http://antoine.frostburg.edu/chem/senese/101/consumer/faq/print-making-soap.shtml