Download Cooking and Additives 31/03/2017 07:48:50 Word Document 560.9

C1f Higher Tier Homework: Cooking and Additives
Question 1
This question is about chemical changes.
(a) Amir is making a cake.
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He adds baking powder to the cake mixture. Baking powder contains sodium hydrogencarbonate. Sodium
hydrogencarbonate breaks down when heated in an oven. Sodium carbonate, water and a gas are the
products made. What gas is made? (1)
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(b) Amir cooks some meat. Meat contains protein. What happens to the protein molecules when the meat is
cooked? (1)
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Question 2
This question is about foods.
(a) Mayonnaise is made by mixing oil, water and egg yolk. Egg yolk acts as an emulsifier and stops the oil and
water from separating. Look at the diagram. It shows a molecule of an emulsifier.
Explain how the emulsifier stops oil and water from separating. (2)
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(b) When eggs are cooked, a chemical change happens. Explain why the texture of the egg changes during this
chemical change. (1)
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(c) Baking powder is used to make cakes rise. Baking powder contains sodium hydrogencarbonate. Sodium
hydrogencarbonate decomposes when it is heated. Write the balanced symbol equation for the
decomposition of sodium hydrogencarbonate. (2)
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