Question

What are chemical changes? With the help of an activity, explain that curdling of milk is a chemical change.

Answer 1

Chemical change - When two or more substances react to form one or more new substances, the change is called a chemical change.

Example- Rusting of iron, ripening of fruit, germination of seeds, digestion of food, etc.

Activity - To understand the curdling of milk is a chemical change.

Material required - a container, some warm milk, some curd.

Procedure -

• Firstly will take warm milk in a container.
• Now add a tablespoon of curd to it and keep it at room temperature overnight.

Observation- We will observe that the milk changes into curd which cannot be changed back to milk.

Conclusion - Through this activity, we can understand that curdling of milk is a chemical change.

Curdling of milk