Neutralisation and Making Salts
Recap Neutralisation and Making Salts for GCSE Chemistry with this free worksheet and full mark scheme — Foundation and Higher exam-style questions with worked answers for AQA, Edexcel and OCR. Acid + base → salt + water; the salt is named from the acid (hydrochloric → chloride, sulfuric → sulfate, nitric → nitrate).
Free downloads
These worksheets and mark schemes are original, written for Virtus Academy and checked against the current AQA, Edexcel and OCR specifications. Every worksheet comes with a full mark scheme.
Topic overview
Neutralisation is the reaction between an acid and a base, producing a salt and water. Bases include metal oxides, metal hydroxides and metal carbonates.
The general equations are: acid + base → salt + water; acid + metal oxide → salt + water; acid + metal hydroxide → salt + water. Carbonates behave slightly differently, giving acid + metal carbonate → salt + water + carbon dioxide.
An alkali is a base that dissolves in water. All alkalis are bases, but not all bases are alkalis — copper oxide is a base but not an alkali, because it is insoluble. That distinction is examined regularly.
Revision notes
The general reactions
Acid + metal oxide → salt + water. Acid + metal hydroxide → salt + water.
Acid + metal carbonate → salt + water + carbon dioxide. The extra product with carbonates is what distinguishes them.
Bases and alkalis
A base is any substance that neutralises an acid.
An alkali is a base that dissolves in water. All alkalis are bases, but not all bases are alkalis — copper oxide neutralises acid but does not dissolve, so it is a base and not an alkali.
Naming the salt
The first part of the salt name comes from the metal in the base.
The second part comes from the acid: hydrochloric gives chloride, sulfuric gives sulfate, nitric gives nitrate. So copper oxide + sulfuric acid → copper sulfate + water.
Key points
- Neutralisation produces a salt and water.
- Bases include metal oxides, hydroxides and carbonates.
- Carbonates also produce carbon dioxide.
- An alkali is a base that dissolves in water.
- All alkalis are bases but not all bases are alkalis.
- The salt name comes from the metal and the acid.
Worked examples
Example 1
Write the word equation for copper oxide reacting with sulfuric acid. [2 marks]
Model answer
Copper oxide + sulfuric acid → copper sulfate + water. Correct reactants (1 mark). Correct products (1 mark).
Example 2
Explain the difference between a base and an alkali. [2 marks]
Model answer
A base is any substance that neutralises an acid (1 mark). An alkali is a base that also dissolves in water, so all alkalis are bases but not all bases are alkalis (1 mark).
Example 3
State the three products formed when a metal carbonate reacts with an acid. [3 marks]
Model answer
A salt (1 mark), water (1 mark) and carbon dioxide (1 mark).
Common mistakes
Saying all bases are alkalis.
Only soluble bases are alkalis. Copper oxide is a base but not an alkali.
Forgetting carbon dioxide with carbonates.
Carbonates give three products, not two.
Naming the salt incorrectly.
First part from the metal, second part from the acid.
Saying neutralisation produces hydrogen.
That is the reaction of an acid with a metal. Neutralisation gives water.
Exam tips
- Learn all four general equations.
- Remember carbonates give an extra product.
- Define alkali as a soluble base.
- Build the salt name from the metal and the acid.
Key terms
- Neutralisation
- The reaction of an acid with a base to form a salt and water.
- Base
- A substance that neutralises an acid.
- Alkali
- A base that dissolves in water.
- Carbonate
- A base that also produces carbon dioxide with acid.
Related topics
Written and reviewed against the current AQA, Edexcel and OCR specifications. Spotted an error? Let us know.