What is litmas paper?

Litmus paper is a type of indicator paper that is used to test for the acidity or alkalinity of a solution. Litmus paper is made from a plant called _Roccella tinctoria_, which contains a natural dye that changes color depending on the pH of the solution. When litmus paper is dipped into an acidic solution, it turns red; when it is dipped into an alkaline solution, it turns blue.

Litmus paper is often used in chemistry labs to test the pH of solutions. Chemists also use litmus paper to test for the presence of acid or base in a given substance.

There are two types of litmus paper: red litmus paper and blue litmus paper. Red litmus paper turns blue when it is dipped into an alkaline solution, and blue litmus paper turns red when it is dipped into an acidic solution.