Question

name a reagent which can be used to distinguish between ethane and ethene?

Answer 1

the reagent is nickel or palladium or platinum

Answer 2

Answer: Bromine water

Explanation: Saturated compound like ethane $CH_3CH_3$ do not undergo addition reactions.

$CH_3CH_3+Br_2(aq)(orange)\rightarrow$ no reaction

But unsaturated compounds such as ethene $CH_2=CH_2$ undergo addition reaction and thus decolonize bromine water as they form addition product.

$CH_2=CH_2+Br_2(aq)(orange)\rightarrow CH_2BrCH_2Br$