Question

Discuss/Explain what an indicator is and its purpose.

Answer 1

An indicator is any organic species that gives a distinct observable change when the conditions in its solution changes. This could be a colour change, precipitate formation, temperature change or any other measurable quantity .

Some indicators changes colour due to change in ph ,they are called acid base indicators.

So basically the purpose of adding indicator to a reaction medium is to notice the progress of reaction I.e to know the completion of reaction by observing a noticeable change in the property of indicator .