Chemistry 9701 · AS & A Level · States of matter

States of matter — practice question

Advantame is a sweetener that is about 2500 times sweeter than sucrose.
(a)[1]

Advantame is optically active. On the diagram of Advantame, circle every chiral carbon atom.

(b(i))[1]

Advantame decomposes to give three molecules, J, K and L. The RO- group in Advantame does not react. Suggest suitable reagents and conditions for this decomposition.

(b(ii))[1]

Name the reaction type taking place.

(b(iii))[1]

Draw the structure of L in the box provided.

(b)

Advantame decomposes to produce three molecules, J, K and L. The RO- group in Advantame is unreactive.

(c(i))[1]

Aqueous bromine was added dropwise to a solution of J until excess bromine was present. State what you would observe.

(c(ii))[2]

J has the molecular formula $\text{C}_{14}\text{H}_{19}\text{O}_6\text{N}$. Use this formula to write an equation for the reaction of excess aqueous sodium hydroxide with one mole of J.

(d(i))[1]

State what you would observe when excess aqueous bromine is added to a solution of K.

(d(ii))[2]

K can be polymerised. Draw the structure of the polymer showing two repeat units. The linkage between the monomer units should be fully displayed.

(e)

Use the *Data Booklet* when answering this question. The carbon-13 NMR spectrum of K was obtained.

(e(i))[1]

State how many chemically different carbon environments there are in K.

(e(ii))[1]

The chemical shifts, $\delta$, due to two of the carbon atoms x and y present in K are given in the table: x = $130$ ppm, y = $170$ ppm. On the structure of K, circle and label two carbon atoms which could correspond to x and y.

Worked solution & mark scheme

This 12-mark question has a full step-by-step worked solution and mark scheme. One marking point: Structure correctly drawn

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