Question

Explain the following terms with one example each.
(a) Corrosion
(b) Rancidity

Answer 1

(a) Corrosion is a natural process, which converts a refined metal to a more stable form, such as its oxide or hydroxide. It is the gradual destruction of metals by chemical reaction with their environment.

Rusting, the formation of iron oxides is a well-known example of electrochemical corrosion.

(b) Rancidity refers to the spoilage of food in such a way that it becomes undesirable and unsafe for consumption. It is the hydrolysis or autoxidation of fats into short-chain aldehydes and ketones which are objectionable in taste and odour.

When rancidity occurs in food, undesirable odours and flavours can result. In some cases, however, the flavours can be desirable (as in aged cheeses).