Question

distinguish between a cmmon acid base indicator and a universal indicator

Answer 1

hello friend,

first acid,base indicators,

i). A substance which liberates H positive ions when dissolved in water is an acid.

ii). A substance which liberates OH negative ions in water is called a base.

iii). Some natural and synthetic dyes show two different colors in acidic and base solution, and such dyes are acid- base indicators.

iv). Blue and red litmus paper are used to the acid or base.

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Universal indicators,

i).A universal indicator is made by mixing several synthetic indicators in specific proportions.

ii). In the pH scale,the pH of solution varies from 0 to 14 in accordance with the strength of the acid or base.

iii). To show these variation in pH,a universal is used.A universal indicator shows different colors at different values of pH.

iv). The pH of a solution can be determined by means of universal indicator solution or the pH paper made from it.

v). However, the most accurate method of measuring the pH of a solution is to use an electrical instrument called pH meter.

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............I hope this will helps you..............

Answer 2

Common acid base indicator : are those indicators which are obtained from nature , like litmus , which are obtained from lichen ( a thalophyta).
In neutral media the colour of Litmus is purple, while acid turns blue Litmus to red and vice versa... there are also some synthetic indicators like methyl orange, phenolphthalein. These all indicators are able to show only one colour at once .. these indicators fails to tell us the relative strength of acids or bases. But

Universal indicators: are mixtures of many different indicators which give different colours at different PH value at the entire pH scale.


Hope it helps...