Question

On adding bromine water to ethyne, the orange colour of bromine disappears due to the formation of ______.

Options

• C₂H₄Br₂

• C₂H₅Br

• C₂H₂Br₂

• C₃Br

Answer 1

On adding bromine water to ethyne, the orange colour of bromine disappears due to the formation of C₂H₄Br₂.

Explanation:

Ethyne (C₂H₂) is an unsaturated hydrocarbon containing a carbon-carbon triple bond that undergoes a halogen addition reaction when mixed with bromine water. One mole of bromine adds across one of the π-bonds of the triple bond, breaking it down into a double bond. This process consumes the molecular bromine (Br₂), converting it into colourless 1,2-dibromoethene (C₂H₂Br₂) and causing the characteristic orange colour to completely disappear.