1 (a) Some foods contain starch - Edexcel - GCSE Biology - Question 1 - 2020 - Paper 1
Question 1
1 (a) Some foods contain starch.
Which chemical is used to test for starch?
A amylase
B ethanol
C iodine solution
D hydrochloric acid
(i) Give two safety p... show full transcript
Worked Solution & Example Answer:1 (a) Some foods contain starch - Edexcel - GCSE Biology - Question 1 - 2020 - Paper 1
Step 1
Which chemical is used to test for starch?
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Answer
The chemical used to test for starch is C iodine solution. Iodine reacts with starch, resulting in a blue-black color.
Step 2
Give two safety precautions needed when doing this test.
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Answer
Always wear safety goggles to protect your eyes from any spills or splashes during the experiment.
Handle test tubes with care, using tongs or a test tube holder to avoid burns or breakage.
Step 3
Give one reason for placing the test tube in boiling water.
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Answer
Placing the test tube in boiling water ensures that the solution reaches a high temperature, which is necessary to facilitate the reaction between iodine and starch.
Step 4
Give one variable the student should control.
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Answer
The student should control the amount of biscuit sample used in each test to ensure that the results are valid and comparable.
Step 5
State two conclusions that can be made from the data in Figure 3.
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Answer
Biscuit A contains a moderate amount of reducing sugar, as indicated by the green color of Benedict's solution.
Biscuit B has a high concentration of reducing sugar, signified by the brick red color, while Biscuit C indicates a low concentration with an orange color.
