Question

If you used a bromine test to distinguish between hexane and 2-hexene, in which would th red color of the bromine persiste?

Answer 1

Explanation;

Bromine test is done to distinguish between the unsaturated hydrocarbons from saturated hydrocarbons.

When we add bromine water to an unsaturated hydrocarbon ,bromine atoms get attached to the carbons with double bond in between. This reaction between bromine water and unsaturated hydrocarbon results in de-colorization of bromine water color from red to colorless.

When bromine water is added to hexane no color change will be observed.

$C_6H_{14}+Br_2\rightarrow$ no reaction

When bromine water is added to 2-hexene color change will be observed.

$CH_3-CH=CH-C_3H_7+Br_2\rightarrow CH_3-CHBr-CHBr-C_3H_7$