Question

1. Hydrochloric acid, sodium hydroxide and sugar solution are given to Ravi.
He is asked to use turmeric as an indicator.
a) How will Ravi identify the basic substance?
b) Give reason for the result obtained by Ravi.​

Answer 1

Answer:

Turmeric is a good indicator of acids and bases. It turns red in bases whereas it is yellow in both acids and neutral solutions. When we mix turmeric to the three liquids, sodium hydroxide turns it into red so we conclude that it is a base. Hydrochloric acid and sugar solution keep turmeric in yellow colour.

Answer 2

a) If Ravi had added turmeric to basic substance he will notice red coloured formation in the basic substance.

b) Turmeric stains are red because of the presence of tartaric acid in it. As tartaric acid is an acid and when it washed with soap which contains sodium hydroxide which is a base.