How can natural indicators be prepared? Explain by giving an example. Class 7

How can natural indicators be prepared? Explain by giving an example. Class 7

Question 1.

How can natural indicators be prepared? Explain by giving an example. Class 7

Answer:

Natural indicators can be made using plant materials with pigments that change colour with acid or base. For example, to make red rose extract:

1. Wash them with water.
2. Crush the petals using a mortar and pestle.
3. Place them in a glass tumbler and add hot water.
4. Let it sit for 5-10 minutes, then filter the mixture.
5. The resulting liquid is a natural indicator that turns red in acids and green in bases.