Soap from Nutmeg: an Integrated Introductory Organic Chemistry Laboratory Experiment
SUPPLEMENTARY MATERIAL
(#2000-0709)
SOAP FROM NUTMEG: AN INTEGRATED INTRODUCTORY ORGANIC CHEMISTRY LABORATORY EXPERIMENT
Marcio C.S. de Mattos and David E. Nicodem
Departamento de Química Orgânica, Instituto de Química,
Universidade Federal do Rio de Janeiro, Caixa Postal 68545
21945-970, Rio de Janeiro, Brazil
1) Written material used by students
2) Instructor notes
3) Chemical abstract registry number of chemicals
1) Written material used by students
Soaps are fatty acid alkali metal salts using linear aliphatic carboxylic acids of from ten to eighteen carbon atoms, the hydrocarbon chain being oil soluble and the carboxylate ion end water-soluble (1). The number of carbon atoms in the chain is very important for the utilization of a soap in cleaning: if it is less than ten carbon atoms, it will not cause emulsification of oil and if more than eighteen carbon atoms are present, the salt is not sufficiently soluble in water to form an adequate colloidal solution (1). Soaps are usually obtained by saponification (basic hydrolysis) of commercially available triglycerides (fats and oils) and their preparation dates back more than five thousand years (2).
[pic]
Trimyristin (glyceryl trimyristate) is a triglyceride easily obtained from nutmeg by extraction with boiling ether (3).
Saponification of trimyristin produces the salt of myristic acid (CH3-(CH2)12-CO2Na) (3), which is a soap (4).
[pic]
Tests with sodium myristate:
1. produces a clean solution when added to a suspension of vegetable oil in water;
2. reacts with calcium salts to produce insolube calcium myristate;
3. reacts with iron(III) salts to produce insolube iron myristate; acidification produces myristic acid, a fatty-acid.
[pic]
Experimental Procedure
Caution! Appropriate safety precautions must be observed (5). Solid NaOH and its strong solutions cause severe burns of the eyes and skin. HCl severely
(#2000-0709)
SOAP FROM NUTMEG: AN INTEGRATED INTRODUCTORY ORGANIC CHEMISTRY LABORATORY EXPERIMENT
Marcio C.S. de Mattos and David E. Nicodem
Departamento de Química Orgânica, Instituto de Química,
Universidade Federal do Rio de Janeiro, Caixa Postal 68545
21945-970, Rio de Janeiro, Brazil
1) Written material used by students
2) Instructor notes
3) Chemical abstract registry number of chemicals
1) Written material used by students
Soaps are fatty acid alkali metal salts using linear aliphatic carboxylic acids of from ten to eighteen carbon atoms, the hydrocarbon chain being oil soluble and the carboxylate ion end water-soluble (1). The number of carbon atoms in the chain is very important for the utilization of a soap in cleaning: if it is less than ten carbon atoms, it will not cause emulsification of oil and if more than eighteen carbon atoms are present, the salt is not sufficiently soluble in water to form an adequate colloidal solution (1). Soaps are usually obtained by saponification (basic hydrolysis) of commercially available triglycerides (fats and oils) and their preparation dates back more than five thousand years (2).
[pic]
Trimyristin (glyceryl trimyristate) is a triglyceride easily obtained from nutmeg by extraction with boiling ether (3).
Saponification of trimyristin produces the salt of myristic acid (CH3-(CH2)12-CO2Na) (3), which is a soap (4).
[pic]
Tests with sodium myristate:
1. produces a clean solution when added to a suspension of vegetable oil in water;
2. reacts with calcium salts to produce insolube calcium myristate;
3. reacts with iron(III) salts to produce insolube iron myristate; acidification produces myristic acid, a fatty-acid.
[pic]
Experimental Procedure
Caution! Appropriate safety precautions must be observed (5). Solid NaOH and its strong solutions cause severe burns of the eyes and skin. HCl severely
Cited: 1. Ikan, R. Natural Products. A Laboratory Guide, 2nd ed.; Academic Press: New York, 1991. pp 26-29.