When a student added red litmus to an aqueous solution, the red litmus turned blue. Which one of the following should be added in exces so that eh change incolour is reversed?

A student added blue litmus solution to a colourless aqueous solution. The solution turned red. Which one of the following chemical should be added in excess so that the change in colour is reversed?

A solution turns red litmus blue its ph is:

Which one of the following will turn red litmus blue ?

Which one of the following changes blue litmus red ?

Blue litmus turns red in

A basic solution turns blue litmus red.

An aqueous solution turns red litmus solution blue. Excess addition of which of the following solution would reverse the change ?