Question

which is changes the blue litmus red​

Answer 1

Answer:

The main use of litmus is to test whether a solution is acidic or basic. Light-blue litmus paper turns red under acidic conditions, and red litmus paper turns blue under basic or alkaline conditions, with the color change occurring over the pH range 4.5–8.3 at 25 °C (77 °F). Neutral litmus paper is purple.