What is the role of an indicator in an acid-base titration? in your answer, identify how an appropriate indicator is chosen and use the terms "end point" and "equivalence point" to explain how an indicator works.

Indicators are used to indicate, by changing colour, when the titration has reached its end point. The equivalence point takes place during a chemical titration when the amount of titrant is equal to the amount of analyte present in the sample. The end point  refers to the point at which the indicator changes color in a colorimetric titration.