Question

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

Answer 1

the colour of litmus paper does not change because
when NaOH reacts with H2SO4 it produces sodium salt I. e NaSO4
thus the reaction becomes neutralise
then the solutions pH value becomes 7 neutral thus the blue litmus paper does not change any colour




hope this will help you ☺

Answer 2

because the reaction become neutralize