A student prepared solution of (i) acid and (ii) base in two separate beakers but forgot to table the solution and litmus paper is not available in the lab. Since both solution are colourless how will you distinguish between there using (a) phenolphthalein (b) methyl orange.

Explanation

(a) When we add phenolphthalein to acid it will be colourless. When we add phenolphalein to base, it burns pink.
(b) When we add methyl orange to acid it turns red. When we add methyl orange to base it turns yellow.