Question

if a red litmus turns blue due to a base can we use this blue litmus for testing an acid ???

Answer 1

yes, it can now be used to test an acid.
this blue paper will turn red in the presence on an acid.
hope it helpzzz u ☺️☺️

Answer 2

Yeah. It can also be used to test an acid. If we test with an acid the blue litmus turns to red.

HOPE IT WORKS