litmus paper

Litmus paper is a type of testing strip used to determine whether a substance is acidic, neutral, or alkaline. It is treated with a special dye derived from lichens that changes color depending on the pH level. When you dip the litmus paper into a liquid, it quickly indicates the nature of the substance: typically turning red in acids, blue in alkalines, and remaining purple in neutral solutions. This simple tool provides a quick, visual indication of pH, making it useful in laboratories and in various practical applications to assess the acidity or alkalinity of liquids.