Salt: GCSE Chemistry Definition

What is a salt?

In GCSE Chemistry, a salt is a compound that forms when the hydrogen atom in an acid is replaced by a metal.

For example, replacing the H in HCl with a potassium atom in potassium hydroxide, makes the salt potassium chloride, KCl. 

HCl (aq) + KOH (aq) → KCl (aq) + H₂O (l)

Uses of salts include fertilisers, batteries, cleaning products, healthcare products and fungicides. 

How to make a salt

The following reactions make salts:

acid + metal ⟶ salt + hydrogen

acid + base ⟶ salt + water

acid + metal carbonate ⟶ salt + water + carbon dioxide

Salts can be soluble or insoluble:

• A soluble salt can be prepared by a titration, using an alkali and an acid, or a reaction between an insoluble base and an acid.

• An insoluble salt can be formed by a precipitation reaction. 

Names of salts

The name of a salt has two parts:

1. The first part is the name of the metal

   • This is from the metal, metal oxide, metal hydroxide or metal carbonate used in the reaction.

2. The second part comes from the acid

   • Hydrochloric acid always produces chloride salts which contain the chloride ion, Cl^-

   • Sulfuric acid always produces sulfate salts which contain the sulfate ion, SO₄^2–

   • Nitric acid always produces nitrate salts which contain the nitrate ion, NO₃^–

Naming salts examples

Salt Revision Resources to Ace Your Exams

For more information about salts, check out the revision notes on salt production. You can also practice our exam questions to ensure success. Our flashcards on reactions of acids are also a great way to revise before an exam.

Explore our GCSE Chemistry Revision Resources.