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

Explanation

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+3O_(2)+nH_(2)O to 2Fe_(2)O_(3)+nH_(2)O`
Rancidity is the process of oxidation of fats and oils that can be easily noticed by the change in taste and smell.
For example, the taste and smell of butter changes when kept for long.