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

Amines react with acid chlorides to produce nitrogen-containing products.

i) State the name of the mechanism for the reaction between ethanoyl chloride, CH₃COCl, and methylamine, CH₃NH₂.

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ii) Describe the mechanism for this reaction. Include all relevant curly arrows, lone pairs, and dipoles.

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iii) State the systematic name of the compound formed in the reaction.

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Methylamine can be prepared from chloromethane.

i) State the reagents and conditions required for this synthesis.

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ii) State the name of the mechanism for this reaction.

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Chloroethane can also react with methylamine.

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

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ii) State the type of amine formed in this reaction.

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Methylamine, CH₃NH₂, and dimethylamine, (CH₃)₂NH, are both soluble in water.

i) Suggest how, other than smell, the two solutions could be distinguished from one another.

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ii) Explain 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.

State which of amines A and D is the stronger base. Explain your answer.

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

Fig. 2.1

i) State which amine, A, B, C, or D, reacted with ethanoyl chloride to form compound E.

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ii) State the name of the inorganic by-product of this reaction.

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iii) State the type of amide formed in this reaction.

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

Fig. 3.1

Explain why cyclohexylamine is not an isomer of hexylamine.

State the relative order of basicity of ammonia, hexylamine, and phenylamine. Explain your reasoning.

most basic ......................... > ......................... > ......................... least basic

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

i) State the name of 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 curly arrows, lone pairs, and dipoles.

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

Draw the skeletal formula of this compound.

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