AT skills covered by this practical activity: AT 2 and 8.

The idea

This statement identifies the apparatus and technique skills developed by the food tests practical. AT 2 covers the safe and correct use of appropriate apparatus and techniques, including using a Bunsen burner, water bath, test tubes, measuring cylinders and dropping pipettes, and handling reagents safely. AT 8 covers making and recording observations, and presenting results appropriately, such as in a results table with the food sample, test carried out and observed colour. When you carry out the practical, you should choose clean apparatus, measure volumes consistently, heat Benedict’s mixtures in a water bath rather than directly, and record what you see accurately. You should also recognise hazards such as ethanol being flammable and iodine staining, and take suitable precautions.

What earns the marks

• Selects and uses appropriate apparatus, such as test tubes, a test-tube rack, measuring cylinders, dropping pipettes and a water bath.
• Uses apparatus safely, including heating Benedict’s mixtures in a water bath and keeping ethanol away from flames.
• Measures volumes of food sample and reagent consistently so that tests on different samples can be compared.
• Makes and records observations accurately, noting the starting colour and the final colour for each test.
• Presents results in a suitable table with columns for the food sample, the test or reagent used and the observed result.
• Identifies relevant hazards and describes suitable precautions, such as wearing eye protection and avoiding contact with iodine or Biuret reagent.

Common mistakes and how to put them right

• Recording only the final colour without the starting colour.

  Put it right: Record both the initial colour of the reagent and the final colour after the test so the change is clear.

• Using a different volume of reagent for each sample.

  Put it right: Use equal volumes of sample and reagent so that comparisons between samples are valid.

• Ignoring safety when using ethanol.

  Put it right: Keep ethanol away from flames and use a water bath rather than a direct flame when heating.

Exam tips

• When a question asks about apparatus or technique, name the specific equipment and explain why it is suitable rather than giving a general answer.
• Draw results tables with clear headings and units where relevant, and leave space to record both initial and final colours.
• Link safety points to the specific hazard, such as flammable ethanol or irritant reagents, to show that you understand the risk.