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


Corrosion is defined as a process where materials, usually metals, deteriorate as a result of a chemical reaction with air, moisture, chemicals, etc.
For example, iron, in the presence of moisture, reacts with oxygen to form hydrated iron oxide.
4Fe + 3O2 + nH2O → 2Fe2O3.nH2O

Rancidity is the process of oxidation of fats and oils that can be easily noticed by the change in taste and smell is known as rancidity.
For example, the taste and smell of butter changes when kept for long.

It is a process of oxidation of metal by acid,moisture,gases etc is called corrosion
for e.g  rustin g of iron
u can prevent it by following method
1 by painting
2 by oil and grease
the oxidation of oils or fats in a food resulting into a bad taste and smell is called rancidity
e.g fungi act on bread