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Required practicals

GCSE Chemistry required practicals explained step by step.

Choose a subject, open a practical, and revise AQA GCSE Science methods through variables, safety, examiner tips, quizzes, model answers and local notes.

What are GCSE required practicals?

GCSE required practicals are experiments students must understand for Biology, Chemistry and Physics. In AQA exams, students may be asked to describe the method, identify variables, explain safety choices, analyse results and suggest improvements.

AQA Chemistry practicals revision

  • Making Salts: Prepare a pure, dry sample of a soluble salt from an insoluble base and an acid.
  • Electrolysis: Investigate the products formed when ionic solutions are electrolysed.
  • Temperature Changes: Measure temperature changes during neutralisation reactions and compare energy transfer.
  • Titration: Find the exact volume of acid needed to neutralise an alkali using an indicator.

AQA GCSE Chemistry practical simulations, examiner tips and exam-style practice.

Foundation & Higher

Making Salts

Prepare a pure, dry sample of a soluble salt from an insoluble base and an acid.

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Here you can read the aim, equipment, safety notes, examiner tips and the first few method steps. The full practical also includes the interactive simulator, mark scheme keywords, a mini quiz, exam-style practice questions and a printable revision summary.

Method

  1. Measure a fixed volume of the acid and pour it into a beaker.
  2. Warm the acid gently.
  3. Add the insoluble base in small masses.
  4. Continue adding until the base is in excess.

Aim

  • Make pure, dry crystals of a soluble salt from an insoluble base and an acid.

Equipment

  • Acid
  • Insoluble base
  • Beaker, tripod, gauze and Bunsen burner
  • Filter funnel and filter paper
  • Evaporating basin
  • Crystallising dish
  • Glass rod

Safety

  • Wear eye protection because acids are irritants.
  • Use gentle heating and keep the Bunsen flame controlled.
  • Handle hot glassware with care.

Common mistakes

  • Adding too little base so acid remains in the final solution.
  • Forgetting that copper sulfate is soluble and passes through the filter.
  • Writing evaporate all the water instead of crystallise the solution.

Examiner tips

Examiner insight

Use the word excess to explain why all acid is neutralised.

Examiner insight

Filtration removes the insoluble reactant, not the dissolved salt.

Examiner insight

Evaporate to the point of crystallisation rather than boiling to dryness.

Variables

Independent
Mass of base added, or type of acid/base depending on investigation.
Dependent
Mass and quality of salt crystals produced.
Control
Volume and concentration of acid, Temperature, Evaporation time, Cooling conditions

Working scientifically

Accuracy
How close the mass of crystals obtained is to the mass predicted from the reacting masses.
Precision
How similar the masses of crystals are if the practical is repeated using the same method.
Reliability
Whether repeating the preparation gives a similar yield and appearance of crystals each time.
Validity
Whether all of the acid has actually reacted, so the crystals collected are a pure sample of the salt.

Common exam questions

  • Why is excess base added?
  • Why is the mixture filtered?
  • Why should the solution not be heated to dryness?

Continue with the full practical

The full version includes the interactive simulator, mini quiz feedback, exam-style practice questions with model answers, saved notes and a print-friendly revision summary.