In a titration, what is the primary function of an indicator?

• A. To precisely buffer the solution so the pH remains constant throughout the titration
• B. To act as the titrant by reacting stoichiometrically with the analyte
• C. To produce a visible change (often a color change) near the equivalence point so the endpoint can be detected
• D. To increase the reaction rate so the titration reaches completion faster

Answer: (C)

Verified step by step guidance

1. Understand that in a titration, the goal is to determine the point at which the amount of titrant added exactly reacts with the analyte, known as the equivalence point.
2. Recognize that the equivalence point itself is a theoretical concept and may not be directly observable without an aid.
3. Learn that an indicator is a chemical substance added in small amounts that changes color at or near the equivalence point, signaling that the titration is complete.
4. Note that the indicator does not buffer the solution or act as the titrant; its role is solely to provide a visible signal (usually a color change) to help detect the endpoint.
5. Conclude that the primary function of an indicator is to produce a visible change near the equivalence point so the endpoint of the titration can be accurately detected.