Question

A hydrocarbon C₄H₈ neither decolourises bromine dissolved in carbon tetrachloride nor reacts with HBr. When heated to 473k with hydrogen in the precence of nickel catalyst , a new hydrocarbon C₄H₁₀ is formed . What is the original hydrocarbon?

Answer 1

The molecular formula of the hydrocarbon represent the following four structural isomers.

Since the hydrocarbon does not decolourise bromine dissolve in CCl₄ and also fails to react with HBr , this mean that it is not unsaturated in nature . The possibility of being an alkene is ruled out. It must be therefore, cyclobutane which reacts with hydrogen to form butane.