Question

what happend when bromine water is added to ethyne ? give chemical reaction involved

Answer 1

Bromine water is brown in colour, when it is treated with ethyne then brown colour of solution decolorise due to the consumption of bromine.
Ethyne undergoes addition reaction with bromine, the equation for the reaction is as follow:-
CH$\equiv$CH + Br₂ ------> CH(Br)=CH(Br),
When ethyne is treated with excess of bromine, then
CH$\equiv$CH + 2 Br₂ --------> CHBr₂-CHBr₂
This test is known as bromine water test and is generally carried out for the determination of unsaturation in an organic compound.