Question

Why a blue litmus does not change colour in a solution of sodium hydroxide and sulphuric acid ?

Answer 1

Bonjour!

In a solution of sodium hydroxide which is a strong base and sulphuric acid which is a strong acid, the solution gets neutalized and the salt is formed which is neutral in nature. Hence, the colour of blue litmus does not change.

Answer 2

When sodium hydroxide is added to sulphuric acid, it forms a salt i.e sodium sulphate. This reaction is a neutralization reaction as both the acid and base are strong and has ph value 7. So, this solution doesn't turn blue litmus red.