Question

) (a) Why ethene decolourises bromine water, but ethane not. (b) Write down the relevant chemical equation involved in decolourisation?

Answer 1

a) ethene is a unsaturated carbon compound and ethane is a saturated carbon compound.
when ethene is in contact with bromine water it goes under addition reaction.
whereas ethane does not. as there is reaction between ethene and bromine water ethene decolorlies bromine water.

b) CH2 = CH2  +Br2 ~~ CH2 (Br)  -- CH2 (Br)

hope it helps!!