Describing salts
I can describe salts and work out their empirical chemical formulae from diagrams, as well as give ionic descriptions of acids and alkalis.
Describing salts
I can describe salts and work out their empirical chemical formulae from diagrams, as well as give ionic descriptions of acids and alkalis.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- A salt is formed when an acid neutralises a base.
- Salts are giant, 3D ionic structures that form crystals with regular arrangements of ions.
- The empirical chemical formula of a salt provides the ratio of metal to non-metal ions it contains.
- Acids contain aqueous hydrogen ions, H⁺(aq) and alkalis contain aqueous hydroxide ions, OH⁻(aq).
- During a neutralisation reaction: H⁺(aq) + OH⁻(aq) → H₂O(l).
Keywords
Salt - An ionic compound formed from positive and negative ions electrostatically attracted to each other.
Empirical formula - Shows the simplest whole number ratio of atoms of each element in a compound.
Acid - A solution that has a pH of less than 7.
Base - Reacts with an acid to form a salt.
Neutralisation - A chemical reaction between an acid and base, producing a solution of a metal salt and water.
Common misconception
Pupils regularly think that neutralisation produces a neutral (i.e. pH 7) solution.
Stress that neutralisation occurs from a complete reaction between an acid and base, which usually occurs between strong acids and strong bases. If a weak acid or weak base is used, the salt solution produced may be alkaline or acidic respectively.
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
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Starter quiz
6 Questions
HCl
H₂SO₄
HNO₃
pH 6
pH 8
a soluble base
cause chemical burns to skin