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Naming SaltsOxford AQA IGCSE Chemistry: Revision notes

Section 1

What determines a salt's name?

A salt is formed when the hydrogen in an acid is replaced by a metal (or ammonium) ion. The name of the salt produced in a reaction between an acid and a base or alkali depends on two things:

  • The acid used (this determines the second part of the salt's name)
  • The metal in the base or alkali (this determines the first part of the salt's name)

For example, sodium hydroxide reacting with hydrochloric acid produces sodium chloride — 'sodium' from the base, 'chloride' from the acid.

Key termssalt

Section 2

Which acid gives which salt?

Each acid produces a characteristic family of salts:

AcidSalt produced
Hydrochloric acidChlorides
Nitric acidNitrates
Sulfuric acidSulfates

These must be learned, as they are used constantly when naming and predicting the products of acid reactions.

Key termschloridenitratesulfate
Exam tip

Examiners award marks for correctly matching acid → salt family, e.g. 'sulfuric acid produces sulfates', even without a full equation.

Section 3

Working out the full salt name

To name a salt fully, combine the metal name (from the base/alkali) with the acid's salt family:

  1. Identify the metal in the base or alkali, e.g. copper in copper oxide
  2. Identify the acid used, e.g. sulfuric acid → sulfate
  3. Combine: copper + sulfate → copper sulfate

If ammonia (not a metal) is used instead of a metal base, the salt is named as an ammonium salt, e.g. ammonia + nitric acid → ammonium nitrate.

Example

Magnesium oxide + hydrochloric acid → magnesium chloride + water.

Example

Potassium hydroxide + nitric acid → potassium nitrate + water.

Section 4

Common naming mistakes

  • Do not confuse 'sulfate' (from sulfuric acid) with 'sulfite' or 'sulfide' — spelling matters
  • Do not confuse 'nitrate' (from nitric acid) with 'nitrite'
  • Remember the metal name always comes first, then the acid-derived name second
Common mistake

Writing 'chloride acid' instead of 'hydrochloric acid', or misspelling 'sulfate' as 'sulphate' (UK exam boards now use 'sulfate').

Must Know

  • The salt produced depends on both the acid used and the metal in the base/alkali
  • Hydrochloric acid → chlorides
  • Nitric acid → nitrates
  • Sulfuric acid → sulfates
  • The salt name = metal name + acid-derived name (e.g. copper sulfate)
  • Ammonia (no metal) produces ammonium salts, e.g. ammonium nitrate

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