Question

Why curdling of milk is a chemical change?

Answer 1

Chemical change:

• A chemical change is a change that results in the formation of new chemical substances by changing the molecular composition of the initial substance.
• It involves the making or breaking of bonds between atoms.
• Generally, chemical changes are irreversible in nature.
• For example, burning paper and wood, food digestion, and egg boiling.

Curdling of milk:

• For the preparation of curd, we boil the milk and add little curd which acts as an inoculum.
• Casein protein present in the milk reacts with the lactic acid present in the curd which breaks the chemical bonds of the milk and forms new bonds thus forming curd.
• Thus, the curdling of milk is a chemical change.