Food tests turn up again and again in 0610 Paper 5 and Paper 6. By hand, measure each food into a test-tube with the syringe, add iodine, Benedict's, biuret or ethanol, carry tubes into the hot water bath, shake the emulsion test and count drops of food into DCPIP. Then describe the colours in exam words, say which nutrients each food contains and rank their sugar and vitamin C. The foods change every attempt. Allow about 30 minutes.
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One mark for each food test row with the correct final colour for all three foods (the test must really be finished at the bench, so Benedict's tubes must stay in the water bath long enough), and one mark for DCPIP drop counts within one drop of your own tubes, with >20 where the blue never went.
One mark for each food: the nutrients you tick must follow from your own observations, so a slip in the table is not punished twice.
The reducing sugar order from the Benedict's colours (blue, green, yellow, orange, brick red = increasing), the food with the most vitamin C and the reason: fewer drops of food decolourise the DCPIP.
Eye protection for hot liquids, no naked flame near ethanol, water in place of food as the control, and the volumes and heating time kept the same.
The marking follows the conventions in published Cambridge mark schemes. The experiments, readings and wording on this page are our own.