Chemistry 9701 · AS & A Level · Analytical techniques

Analytical techniques — practice question

Although Alexander Borodin is now chiefly remembered for his music, he was a Russian chemist. He is credited with discovering the aldol reaction, one product of which is compound $J$. $J$ has the following properties: • its molecular formula is $\text{C}_4\text{H}_8\text{O}_2$ • it is neutral, • it reacts with sodium metal, • it reacts with Fehling's solution, • it does not react with aqueous bromine.
(a(i))[1]

Suggest which functional group is causing the reaction with sodium.

(a(ii))[1]

Suggest which functional group is responsible for the reaction with Fehling's solution.

(b)[1]

The bromine test result indicates that a functional group is missing from compound $J$. Suggest what this functional group is.

(c)[3]

In the boxes below, draw three straight-chain structures for $J$ that satisfy the results above and are structural isomers of one another.

(d(i))[1]

Compound $J$ reacts with alkaline aqueous iodine to produce a pale yellow precipitate. Which functional group does this reaction show that $J$ has?

(d(ii))[1]

Which one of your three structures $K$, $L$ or $M$ contains this group and is therefore $J$?

(e(i))[1]

Compound $J$ exists as stereoisomers. Name the kind of stereoisomerism shown by $J$.

(e(ii))[1]

Draw two structures of $J$ that demonstrate this stereoisomerism.

Worked solution & mark scheme

This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: Na reacts with the -OH / hydroxyl / alcohol group

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