Write the equation for butylamine reacting with water.

CH₃CH₂CH₂CH₂NH₂ + H₂O ⇌ CH₃CH₂CH₂CH₂NH₃⁺ + OH⁻, giving an alkaline solution.

What forms when phenylamine reacts with hydrochloric acid?

Phenylammonium chloride, C₆H₅NH₃⁺Cl⁻, an ionic salt.

Why are short-chain amines miscible with water?

They form hydrogen bonds with water via the N–H hydrogen and the lone pair on nitrogen.

Rank ammonia, butylamine and phenylamine by basicity.

Butylamine ammonia phenylamine.

Why is butylamine a stronger base than ammonia?

The alkyl group releases electrons (positive inductive effect), so the lone pair on N is more available.

Why is phenylamine a weaker base than ammonia?

The N lone pair is delocalised into the benzene ring, so is less available to accept H⁺.

What type of reaction occurs between an amine and a halogenoalkane?

Nucleophilic substitution; the N lone pair attacks the δ+ carbon.

Why does reaction with a halogenoalkane give a mixture of products?

The product amine is still a nucleophile, so further substitution gives secondary, tertiary amines and quaternary ammonium salts.

What is formed from an amine and ethanoyl chloride?

An N-substituted amide plus HCl, e.g. N-butylethanamide.

What is seen when aqueous butylamine is added to copper(II) sulfate, first a little then in excess?

A pale blue precipitate, then a deep blue solution of a complex ion.

Amines: properties and reactionsEdexcel International A Level Chemistry: Flashcards

Card 1 of 120 of 12 known

Question

Name CH₃CH₂CH₂CH₂NH₂.

Tap or press Space to reveal

Tap card or press Space to flip

See all 12 cards

Name CH₃CH₂CH₂CH₂NH₂.: Butan-1-amine (butylamine), a primary amine.
Write the equation for butylamine reacting with water.: CH₃CH₂CH₂CH₂NH₂ + H₂O ⇌ CH₃CH₂CH₂CH₂NH₃⁺ + OH⁻, giving an alkaline solution.
What forms when phenylamine reacts with hydrochloric acid?: Phenylammonium chloride, C₆H₅NH₃⁺Cl⁻, an ionic salt.
Why are short-chain amines miscible with water?: They form hydrogen bonds with water via the N–H hydrogen and the lone pair on nitrogen.
Rank ammonia, butylamine and phenylamine by basicity.: Butylamine > ammonia > phenylamine.
Why is butylamine a stronger base than ammonia?: The alkyl group releases electrons (positive inductive effect), so the lone pair on N is more available.
Why is phenylamine a weaker base than ammonia?: The N lone pair is delocalised into the benzene ring, so is less available to accept H⁺.
What type of reaction occurs between an amine and a halogenoalkane?: Nucleophilic substitution; the N lone pair attacks the δ+ carbon.
Why does reaction with a halogenoalkane give a mixture of products?: The product amine is still a nucleophile, so further substitution gives secondary, tertiary amines and quaternary ammonium salts.
What is formed from an amine and ethanoyl chloride?: An N-substituted amide plus HCl, e.g. N-butylethanamide.
What is seen when aqueous butylamine is added to copper(II) sulfate, first a little then in excess?: A pale blue precipitate, then a deep blue solution of a complex ion.
Name CH₃CONHCH₃.: N-methylethanamide.

Exam questions on Amines: properties and reactions

A technician is preparing 0.10 mol dm⁻³ solutions of ethylamine, CH₃CH₂NH₂, ammonia and phenylamine, C₆H₅NH₂, so that their behaviour with water can be compared. Ethylamine is a gas at room temperature that dissolves freely in water to give an alkaline solution.
Explain why ethylamine is miscible with water.2 marks
Butylamine, CH₃CH₂CH₂CH₂NH₂, is used by a pharmaceutical company as a starting material. It is converted into a range of nitrogen-containing products by reacting it with different organic reagents.
Write an equation, using structural formulae, for the reaction of butylamine with ethanoyl chloride, and name the organic product.2 marks
Phenylamine, C₆H₅NH₂, is a primary aromatic amine used in the manufacture of dyes. A student compares phenylamine with butylamine by measuring the pH of separate solutions of the same concentration and finds that the butylamine solution has the higher pH.
Explain why phenylamine is a much weaker base than butylamine.3 marks

See the full worksheet

Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).