Neutralisation is defined as the reaction in which an acid and a base react together to form a salt and water. Explain what happens during the neutralisation of hydrochloric acid with sodium hydroxide solution, and name the salt produced.

Pearson Edexcel International GCSE Chemistry (4CH1) — 3.4 Acids, alkalis and salts · Explain · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Hydrochloric acid is a strong acid. When it is mixed with sodium hydroxide solution, neutralisation occurs.

Model answer (4 marks)

The reaction is a neutralisation: the H⁺ ions from the acid combine with the OH⁻ ions from the base to give water.
The overall equation is:
HCl + NaOH → NaCl + H₂O
Thus a salt, sodium chloride, is produced along with water.

Examiner tips

  • Use the term ‘neutralisation’ and state the acid–base reaction. Show the ion‑pairing of H⁺ and OH⁻. Write the balanced equation. Name the salt produced.
  • common_mistakes
  • :
  • Writing the reaction as HCl + NaOH → NaCl + H₂O without explaining the ion exchange. Forgetting to mention that water is formed. Using the wrong salt name (e.g. ‘sodium chloride’ instead of ‘NaCl’).

Mark scheme (4 marks)

  1. The acid and base react together (to form a salt and water) / neutralisation is the reaction between an acid and a base
  2. Water is formed as a product of the reaction
  3. The hydrogen ions (H⁺) from the acid react with the hydroxide ions (OH⁻) from the alkali to form water
  4. The salt produced is sodium chloride

Key terms in this question

neutralisation · acid · base · salt

Related

More Acids, alkalis and salts questions

▶ Try answering this question with AI marking (free) →