A-LevelChemistryNitrogen and sulfur9701/41 · May/June 2018 · Q95 Marks

Noradrenaline is a hormone found in humans. [Figure of noradrenaline structure]

(a)Give the molecular formula of noradrenaline.[1]
(b)State whether or not noradrenaline shows stereoisomerism. Explain your answer.[1]
(c)(i)HNO2(aq) is reacted at 5°C with separate samples of noradrenaline and phenylamine. The reaction with phenylamine produces a stable diazonium ion. The reaction with noradrenaline produces an unstable diazonium ion. Suggest why the diazonium ion produced with phenylamine is stable.[1]
(c)(ii)When one noradrenaline molecule reacts with one HNO2 molecule, the products are one water molecule, one molecule of an unreactive gas, and one molecule of an organic compound made up of carbon, hydrogen and oxygen only. Complete the chemical equation for this reaction. [Figure for equation][2]

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Mark scheme

Marking points from the official mark scheme (May/June 2018). The mark or mark type is shown in brackets.

[1] C8H11O3N
[1] yes, as it has a chiral C atom
[1] (phenyldiazonium ion is stabilised because) positive charge is delocalised by ring / positive charge is spread over ring
[1] [Structure with CH2OH instead of CH2NH2]
[1] N2

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