amines

What is an amine?

A derivative of ammonia with one or more hydrogens replaced by alkyl groups.

What is the functional group of an amine?

-NH₂.

What is the general formula of a primary amine?

RNH₂.

What suffix is used to name amines?

-amine.

Why are amines basic?

The nitrogen lone pair can accept a proton.

What is the Brønsted-Lowry definition of a base?

A proton acceptor.

What happens when an amine reacts with water?

Forms an alkaline solution.

What ion is produced when an amine accepts a proton?

RNH₃⁺.

Why are aliphatic amines more basic than ammonia?

Alkyl groups donate electron density to nitrogen.

How are primary aliphatic amines made?

Reaction of ammonia with halogenoalkanes.

Why is excess ammonia used when making amines?

To reduce further substitution.

What is phenylamine?

An amine attached directly to a benzene ring.

Why is phenylamine less basic than ammonia?

The lone pair is partially delocalised into the benzene ring.

How can amines form salts?

By reacting with acids.

What is formed when ethylamine reacts with HCl?

Ethylammonium chloride.

What is diazotisation?

The reaction of phenylamine with nitrous acid.

What temperature is used in diazotisation?

Below 10°C.

What is formed when phenylamine is diazotised?

A diazonium salt.

What is a coupling reaction?

A reaction of a diazonium ion with an aromatic compound.

What is produced by coupling reactions?

Azo dyes.

Why are azo dyes coloured?

They contain extensive delocalised electron systems.

What feature makes amines soluble in water?

The ability to form hydrogen bonds with water.

What colour change occurs when an amine is added to universal indicator?

The indicator shows an alkaline colour.