Write briefly the polymerisation reactions of alkynes.
Alkynes acetylene is passed through a solution of cuprous chloride and ammonium chloride in hydrochloric acid, two molecules are joined together to form vinyl acetylene.
(ii) When vapours of acetylene are passed through red hot iron tube at 773 K, three molecules polymerise to form benzene
(iii) When vapours of acetylene polymerise in the presence of nickel cyanide and under high pressure, four molecules are joined together to form cyclooctatetraene.
Arrange benzene, n-hexane and ethyne in decreasing order of acidic behaviour. Also give reason for his behaviour.
Give simple chemical test for the distinction of:
(i) Propyne and propane
(ii) But-1-yne and But-2-yne.