Today synthetic indicators are the choice of acid-base titrations but due to environmental pollution, availability and cost, the search for natural compounds as an acid-base indicator was started. Indicators help to determine the equivalence point in acid–base titrations (neutralization titrations). They show sharp color change with respect to change in pH; commonly used indicator for neutralization titrations is synthetic in nature. The highly colored pigments obtained from plants are found to exhibit color changes with variation of pH. The chemical substances which possess an apparent change in color of analyte and titrant reacting mixture very close to the point in the ongoing titration known as indicator. Acid-base indicators are the substances which changes color with changes in pH. They are usually weak acids and bases and also known as neutralization indicator. Today various plants extracts are used as acid base indicator such as Rosa sinensis, Dahlia pinnata and Butea monosperma etc. These indicators are economically and easily available. In this review importance of pH indicators in analytical chemistry along with the use of plant material or the extracts obtained from plant is described.
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