Chemistry 9701 · AS & A Level · Hydroxy compounds

Hydroxy compounds — practice question

Compound Q, heptan-2-one, is present in some blue cheeses. Q has the formula $\text{CH}_3(\text{CH}_2)_4\text{COCH}_3$.
(a(i))[3]

In the boxes below, show the structural formulae of R, S and T obtained when Q is reduced to R and R undergoes dehydration to produce two different products S and T.

(a(ii))[2]

State the reagents that would be used for each reaction in a school or college laboratory: reduction; dehydration.

(b)[3]

In the boxes below, write the structural formula of the organic compound formed when Q is reacted separately with each reagent under suitable conditions. If you think no reaction occurs, write NO REACTION in the box. The reagents are Tollens’ reagent, HCN, and $\text{K}_2\text{Cr}_2\text{O}_7/\text{H}^+$.

(c)[2]

Apart from using a pH indicator, what reagent could you use to confirm the presence of some lactic acid in a sample of heptan-2-one? State the observation you would make.

Worked solution & mark scheme

This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: Accurate reduced alcohol $\mathrm{CH_3(CH_2)_4CH(OH)CH_3}$

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