Question

What are Indicators? Explain different indicators with their functions.

Answer 1

the substances that are used to test whether the substances are acids or bases are called indicators
they are 4 types of indicators:
1) natural indicators : the indicators which are prepared from extract of lichens, other natural substances
ex: red,blue litmus, turmeric paper
2) synthetic indicators: they are made artificially
ex: phenolphthalein solution, methyl orange
3) olfactory indicators: the indicators which changes their odour when the are added to acid/base
ex: venella assence, clove oil , onion
4) universal indicator: it is the pH paper,pH solution which changes colour to different colours

Answer 2

indicator is a dyr that changes colour when it is put into acid or bade. it gives different colour in acid and base.
1 natural indicator eg litmus,turmeric (litmusneutralcolour is purple),red cabbage extract.
2 synthetic indicators eg methyl orange and phenolphthalein
methyl orange indicator gives red colour in acid solution
yellow colour in basic solution

ohenolphthalein is colourless inacid solution and pink colour in basic solution


3 olfactory indicator are substances whose smell or odour changes in acidic or baduc solutions.eg vannila extract or onion.
4 universal indicators is a mixture of many different indicators which gives different colours at different ph values of the entite ph scale.