lackmuspapper

Litmus paper is a type of paper that is used as a pH indicator, changing color in the presence of acids or bases. It is made from a mixture of litmus (a water-soluble dye extracted from lichens) and paper. The most common form of litmus paper is blue, but it can also be red or purple. When exposed to an acidic solution, blue litmus paper turns red, while red litmus paper turns blue in the presence of a basic solution. Purple litmus paper remains purple in neutral solutions but turns red in acids and blue in bases. Litmus paper is widely used in laboratories and educational settings to test the acidity or alkalinity of substances. It is a simple and inexpensive method for determining the pH of a solution.