Hydrocarbons 2 Question 66
71. When gas $A$ is passed through dry $\mathrm{KOH}$ at low temperature, a deep red coloured compound $B$ and a gas $C$ are obtained. The gas $A$, on reaction with but-2-ene, followed by treatment with $\mathrm{Zn} / \mathrm{H}_{2} \mathrm{O}$ yields acetaldehyde. Identify $A, B$ and $C$.
$(1994,3 M)$
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Solution:
- $\mathrm{CH}{3}-\mathrm{CH}=\mathrm{CH}-\mathrm{CH}{3} \xrightarrow[\mathrm{Zn}-\mathrm{H}{2} \mathrm{O}]{\mathrm{Gas} A} 2 \mathrm{CH}{3}-\mathrm{CHO}$
$\therefore$ Gas $A$ is ozone $\left(\mathrm{O}_{3}\right)$
Also; Gas $A+\mathrm{KOH}$ (dry) $\longrightarrow \underset{\text { deep red coloured }}{B}+$ Gas $C$
$\therefore 4 \mathrm{O}{3}+4 \mathrm{KOH} \longrightarrow \underset{B}{4 \mathrm{KO}{3}}+\underset{C}{2 \mathrm{H}{2} \mathrm{O}}+\underset{2}{\mathrm{O}{2}}$
