Litmus

Litmus is a tool used to test the acidity or alkalinity of a solution, typically in chemistry or biology. It involves a special paper treated with a natural dye that changes color when in contact with acids or bases. For example, the paper turns red in acidic solutions and blue in alkaline solutions. This quick, simple test helps determine the pH level of a substance, which is important in various scientific, industrial, and environmental applications to ensure safety, quality, or proper conditions.