Primary & Secondary Amines (Cambridge (CIE) A Level Chemistry): Exam Questions

Amines will react with acid chlorides to produce a different nitrogen containing product.

i) Name and outline the mechanism between ethanoyl chloride, CH₃COCl and methylamine, CH₃NH₂.

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ii) Give the IUPAC name of the compound formed in the reaction.

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Methylamine can be prepared from chloromethane.

i) Give the other reagent, and any reaction conditions necessary for the preparation of methylamine.

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ii) Give the name of the mechanism between chloromethane and the other reagent to form methylamine.

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Chloroethane can also react with methylamine.

i) Draw the displayed formula of the organic compound formed in this reaction.

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ii) Give the classification of this compound.

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Two separate solutions of methylamine, CH₃NH₂ and dimethylamine, (CH₃)₂NH, were left unlabelled in a laboratory.

i) Suggest how, other than smell, they could be distinguished from one another.

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ii) Give an explanation to your answer to part (i).

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The structural formulae of four isomeric amines, A - D, with the molecular formula C₃H₉N are given in Table 2.1.

Table 2.1

Complete Table 2.1 to give the name and type of each amine. Each amine is primary, secondary or tertiary.

Predict whether amine A or D is a stronger base. Explain your answer. 

Fig. 2.1 shows compound E, which can be formed by the reaction of ethanoyl chloride with one of the amines from Table 2.1.

Fig. 2.1

Identify the amine, A - D, that reacted with ethanoyl chloride to form compound E and name the byproduct of the reaction and the functional group that is formed.

Amine used in the reaction: ..............................

Byproduct of the reaction: ..............................

Functional group formed: ..............................

The structures of hexylamine and cyclohexylamine are shown in Fig. 3.1.

Fig. 3.1

Explain why cyclohexylamine is not an isomer of hexylamine.

Compare the relative basicities of ammonia, hexylamine and phenylamine.

Explain your reasoning.

Hexylamine reacts with ethanoyl chloride, CH₃COCl, to form an amide.

i) Name the mechanism for this reaction.

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ii) Complete the mechanism of the reaction between hexylamine and ethanoyl chloride.

Hexylamine is represented by R–NH₂.

Include all relevant lone pairs of electrons, curly arrows, charges and partial charges.

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iii) Hexylamine reacts with an excess of ethanoyl chloride to form another compound with the molecular formula C₁₀H₁₉NO₂.

Draw the structure of this compound.

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