Question

give a test test to differentiate saturated and unsaturated compound

Answer 1

Heya friend!!
Rajdeep here......

What are saturated compounds?
They are the hydrocarbons with single bonds which can show substitution reaction.

What are unsaturated compounds?
They are hydrocarbons with double or triple bonds which can show addition reaction.

Thus, alkanes are saturated whereas alkenes and alkynes are unsaturated.

Test to distinguish between them:
1. Add Bromine solution with Carbon Tetrachloride: With alkanes, there is no observation. Alkenes and alkynes change the colour of bromine solution (with CCl4 mixed) from brown to colourless.

2. Add Alkaline Potassium permanganate solution. With alkanes, there is no observation. Alkenes and alkynes change its colour from pink (or purple) to colourless.

Thanks!! 

Answer 2

Answer. When saturated compounds are burnt in air, they give a clear (blue) flame but the burning of unsaturated compounds (akenes and alkynes) gives a sooty (yellowish) flame. Actually, saturated compounds contain comparatively less percentage of carbon which get completely oxidized by the oxygen present in air. On the other hand, the percentage of carbon in unsaturated compounds is more and it requires more oxygen to get completely oxidized that is not fulfilled by air. So due to incomplete oxidation they burn with a sooty flame.

Bromine-water test:  Br2water is a brown coloured liquid.
(a) Unsaturated hydrocarbons give addition reaction with Br2. So the colour of Br2-water gets decolourized.
            R-C=C-R + Br2 →R-BrC-CBr-R

(b) Saturated hydrocarbons do not react with Br2-water, so the colour of Br2.-water does not get decolourised .