Question

Define Universal Indicator and for what purpose it is used?

Answer 1

In order to answer this question, first we will describe the concept of Universal Indicator and we will also explain the different forms of universal indicator. And then we will mention the purpose or the uses of Universal Indicator.

Complete answer:
A pH indicator formed of a solution of many compounds that exhibits several smooth colour changes across a wide range of pH values to indicate the acidity or alkalinity of solutions is known as a universal indicator. Despite the fact that there are multiple commercially available universal pH indicators, the most of them are variations on a Yamada formula patented in 1933. Chemical Abstracts has more information about this patent. In the Journal of Chemical Education, experiments with Yamada's universal indicator are also discussed.
A universal indicator is usually composed of water, $1 - Propanol$ , phenolphthalein, sodium hydroxide, methyl red, bromothymol blue, Sodium bisulfite, and thymol blue .
A universal indication is a collection of indicators that display a colour shift in a solution and may be used to determine whether a solution is acidic or basic. A universal indicator can be in the form of a solution or on paper.
Paper Form:- It's a piece of coloured paper that turns red when the solution is acidic and blue when the solution is basic. The strip can be placed directly on a wet substance's surface, or a few drops of the solution can be dropped onto the universal indicator with the use of dropping equipment. If the test solution is dark in colour, a paper universal indicator is preferable.