Question

A hydrocarbon A on chlorination gives B which on heating
with alcoholic potassium hydroxide changes into another
hydrocarbon C. The latter decolourises Baeyer's reagent and
on ozonolysis forms formaldehyde only. A is
(a) Ethane (b) Butane
(c) Methane (d) Ethene

Answer 1

The hydrocarbon A is a) Ethane.

• Ethane is a colourless, odourless, and a flammable gas with a C2H6 chemical formula, consisting of two atoms of carbon (C) and six atoms of hydrogen (H)
• A chlorinated ethane gives the compound 1-chloroethane, which converts to a dehydro-halogenation product called Ethene with the alcoholic KOH.
• Thus, the ethene formed from this process is further subjected to ozonolysis to break the double bond and form two formaldehyde molecules.