Question

Why does a blue litmus papaer turn red in acid? Whay does a red litmus paper turn blue under basic conditions. What actually happens ? It woud be nice if you could explain it at molecular level.

Answer 1

Acid turns blue litmus paper red. Bases turn red litmus paper blue. This is true because the original color of litmus is blue.

During manufacture, the red litmus paper is mixed with an acid to turn it red. When red litmus comes into contact with a base, it returns to its original blue shade.

The dyes obtained from lichens are responsible for this change in color.