Ravi's father is a Botanist. He extracted a purple dye from a plant in

1.	Ravi's father is a Botanist. He extracted a purple dye from a plant in the laboratory which acts as an acid base indicator. When he adds this purple dye with acids, it changes to red colour. But when a small amount of base is added to this dye, it changes its colour to blue. Ravi was very excited to see that colours were changing accordingly with the solution. He observed the magic and asked some questions from his father. (i) What is a indicator ? (ii) Name the plant from which his father extracted the dye. (iii)'Some natural substances are good source of indicators.' Suggest some examples to justify the statement
Answer» (i) Indicators are the substances which change their colour in different types of substances. (ii) Lichen. (iii) Examples of natural indicators : (a) Beetroot extract shows same colour in all sour substances and a different colour in bitter substances. (b) Turmeric gives a yellow spot on a cloth but when washed with soap, the colour of the spot changes to red.

Ravi's father is a Botanist. He extracted a purple dye from a plant in the laboratory which acts as an acid base indicator. When he adds this purple dye with acids, it changes to red colour. But when a small amount of base is added to this dye, it changes its colour to blue. Ravi was very excited to see that colours were changing accordingly with the solution. He observed the magic and asked some questions from his father. (i) What is a indicator ? (ii) Name the plant from which his father extracted the dye. (iii)'Some natural substances are good source of indicators.' Suggest some examples to justify the statement

Answer»

(i) Indicators are the substances which change their colour in different types of substances.

(ii) Lichen.

(iii) Examples of natural indicators :

(a) Beetroot extract shows same colour in all sour substances and a different colour in bitter substances.

(b) Turmeric gives a yellow spot on a cloth but when washed with soap, the colour of the spot changes to red.