Question

what is the effect of acid and bas on the following indicators-
(I) Litmus
(ii) Methyl orange
(iii) Phenophalein

Answer 1

Methyl orange gives red colour but in basic solution it gives yellow colour . In Acidic solution phenolphthalein is colourless but in basic it gives pink colour . Blue litmus paper turns red under acidic conditions and red litmus paper turns blueunder basic or alkaline conditions.

Answer 2

Methyl orange is a pH indicator frequently used in titration because of its clear and distinct colour variance at different pH values. Methyl orange shows pink colour in acidic medium and yellow colour in basic medium. Because it changes colour at the pH of a mid strength acid, it is usually used in titration for acids. Unlike a universal indicator, methyl orange does not have a full spectrum of colour change, but it has a sharp end point.