Chemistry 9701 · AS & A Level · Hydroxy compounds

Hydroxy compounds — practice question

Crotyl alcohol, $\text{CH}_3\text{CH}=\text{CHCH}_2\text{OH}$, is a colourless liquid that serves as a solvent.
(a)[5]

In the spaces provided below, give the structural formula of the organic product formed when crotyl alcohol is treated separately with each reagent under suitable conditions. If no reaction takes place, write "NO REACTION" in the box. (A) $\text{Br}_2$ in an inert organic solvent (B) $\text{PCl}_5$ (C) $\text{H}_2$ and Ni catalyst (D) $\text{NaBH}_4$ (E) $\text{K}_2\text{Cr}_2\text{O}_7/\text{H}^+$, heat under reflux

(b)[1]

Draw the displayed formula of the organic product formed when crotyl alcohol reacts with cold, dilute acidified potassium manganate(VII).

(c)[2]

Draw the skeletal formula of the compound formed in reaction E.

(d(i))[2]

Describe one test that would confirm the presence of a small amount of unreacted crotonaldehyde in the crotyl alcohol. Name the reagent used and state the observation.

(d(ii))[1]

What kind of reaction is the conversion of crotonaldehyde into crotyl alcohol?

(e)[2]

The percentage composition by mass of compound P is C: $73.7\%$; H: $12.3\%$; O: $14.0\%$. Calculate the empirical formula of compound P.

Worked solution & mark scheme

This 13-mark question has a full step-by-step worked solution and mark scheme. One marking point: Reaction A: $\mathrm{Br_2}$ in inert organic solvent forms $\mathrm{CH_3CHBrCHBrCH_2OH}$

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