Question

An organic liquid '$A$' containing $C,H$ and $O$ with boiling point ${78}^{o}C,$ possessing a rather pleasant colour, on heating with concentrated sulphuric acid gives a gaseous product '$B$' with the empirical formula, $C{H}_2$. '$B$' decolourises bromine water as well as alkaline permanganate solution and takes up one mole of $H_2$ (per mole of $B$) in presence of finely divided nickel at high temperature. Identify the substances $A$ and $B.$

• A. Ethanol, Ethene
• B. Ethanal, Ethyne
• C. Glycol, Ethyne
• D. Propanol, Propene

Answer 1

The correct option is A Ethanol, Ethene

Since '$B$' decolourises bromine water as well as alkaline permanganate solution and takes up one mole of $H_2$ (per mole of $B$) in presence of finely divided nickel at high temperature, $B$ is an alkene.
$A$ can either be ethanol or propanol. The boiling point of ethanol is ${78}^{o}C.$ Hence, $A$ is ethanol and $B$ is ethene.