Question

a) What are indicators? b) What is the effect of sulphuric acid on the following? i.Red litmus ii. Blue litmus iii. Phenolphthalein (c) Why should you not try to wash off a turmeric stain on your clothes with soap?

Answer 1

(a) Indicators are Substances which are used to make suitable amount of making in required amount of solutions to give acidity or basicity. Natural indicators are White Colour of Egg and White Colour of Horn of Animal. Synthetic indicators are Sodium Nitrate and Magnesium Sulphate.

(b) The Effect of Sulphuric acid are
Red litmus           - No Change
Blue litmus          - Change its colour to red
Phenolphthalein - No Change.