Question

What is the role of indicators in the titration process?

Answer 1

Hint: Titration is the process used in the quantitative analysis of any substance in chemistry. This analysis usually tells us the concentration and strength of a substance or solution in the terms of molarity or molality of a chemical compound. Indicators are compounds that change their colour in response to the changes in the surrounding chemical it is used..

Complete Step by Step Solution:
Titration is the quantitative analysis of any provided sample. The titration can be acid-base type (the most usual ones). It can also be redox or of any other type. In the titration procedure, an indicator is used. This is added to the analyte(a substance that is being analysed), it is added to the flask, and to this, the titrant(a substance added to the solution for titration) from the burette is added.

The indicator is the substance that changes or imparts a certain colour at the stoichiometric end point of the titration. This means that when a specific concentration of acid or base is totally neutralised, we see a colour change at the endpoint. Usually, the chemical phenolphthalein is used as an indicator in titration.

Note: Methylene orange, in addition to phenolphthalein, is employed as an indication. It changes colour when pH changes. In an acidic solution, it is red, whereas, in a basic solution, it is yellow. It is used for the titration of acids. At pH = 7, the titration of strong acids and strong bases reaches equivalence. At pH > 7, weak acids and strong bases have equivalence points. Strong acid and weak base titrations have equivalence points at pH 7, while strong acid and weak base titrations have equivalence points at pH 7.