1 What are universal indicators and what are their uses?
Answers
Answer:
it is the mixture of indicators. it is used to know that how an substance is acidic or basic by changing it's colour
Answer:
A universal indicator is a pH indicator made of a solution of several compounds that exhibits several smooth colour changes over a wide range pH values to indicate the acidity or alkalinity of solutions. Although there are several commercially available universal pH indicators, most are a variation of a formula patented by Yamada in 1933.[1] Details of this patent can be found in Chemical Abstracts.[2] Experiments with Yamada's universal indicator are also described in the Journal of Chemical Education.[3]
A universal indicator is typically composed of water, propan-1-ol, phenolphthalein sodium salt, sodium hydroxide, methyl red, bromothymol blue monosodium salt, and thymol blue monosodium salt.[4] The colours that indicate the pH of a solution, after adding a universal indicator, are:
Explanation
pH range Description Colour
< 3 Strong acid Red
3–6 Weak acid Orange or yellow
7 Neutral Green
8–11 Weak alkali Blue
> 11 Strong alkali Violet or Indigo