Indicator

Definition

An indicator is a substance that undergoes distinct color changes or other measurable changes when it reacts with specific substances in solutions. Indicators are used in titrations as visual cues to determine when reactions between solutions are complete.

Related terms

pH indicator: A type of indicator that changes color depending on whether a solution is acidic or basic.

Methyl orange: A commonly used pH indicator that turns red in acidic solutions and yellow in basic solutions.

Phenolphthalein:

Another commonly used pH indicator that is colorless in acidic solutions and pink in basic solutions.