Carboxylic acids, esters, fats and oils

Carboxylic acids are produced by oxidation of alcohols.There are many naturally occuring organic acids - the ones with more carbon atoms often have unpleasant smells, including body odour.

Some of the difficulties that students have with organic chemistry are due to the unfamilar names, structures and confusion over IUPAC and common nomenclature. Often the organic compounds are referred to by their common name rather than their systematic name. It should be pointed out to students that it is conventional to write a formula with COOH rather than CO2H (although this is not wrong) as it conveys structural information.

The importance of carboxylic acids is related to their reactivity and their use in making other useful compounds used in a wide range of applications e.g. making esters, fats and oils. Carboxylic acids are weak acids because the dissociation is not complete and the position of the equilibrium lies more to the left. Weak acids are sometimes preferable to strong acids in order to limit the possibility of corrosion or other damage which a strong acid may produce. Hence ethanoic acid is used in household descaling products.

In the food industry there are many carboxylic acids, and compounds containing –COOH groups. Citric acid, malic acid and tartaric acid are widely used examples. In the pharmaceutical industry many carboxylic acids are used in the synthesis of complex drug molecules. There are many polymers whose manufacture requires carboxylic acids. Nylon is one example, using a dicarboxylic acid.

Whilst this list provides a source of information and ideas for experimental work, it is important to note that recommendations can date very quickly. Do NOT follow suggestions which conflict with current advice from CLEAPSS, SSERC or recent safety guides. eLibrary users are responsible for ensuring that any activity, including practical work, which they carry out is consistent with current regulations related to Health and Safety and that they carry an appropriate risk assessment. Further information is provided in our Health and Safety guidance.