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01057_Text_GCSE Activity Window Template.txt
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Exhibition of molecules makes novel departure for Gatwick
1. One of the captions for this article is "A jug of simple H2O molecules"
Use your knowledge of water molecules to explain why water molecules are indeed H2O, but are far from simple.
You might like to include in your explanation:
Electronic configuration of hydrogen and oxygen.
Repulsion of lone and bonded pairs.
Hydrogen bonding.
Anomalous properties of water.
2. Sugar is an example of a carbohydrate. It is more correctly called sucrose and it is a disaccharide. One component of sucrose is glucose.
a) What is meant by a disaccharide?
b) Draw glucose in both its open chain and ring structure.
c) In the laboratory test a number of sugars by boiling a little with about 10ml of Benedicts solution in a boiling tube.
(REMEMBER TO WEAR EYE PROTECTION)
Try glucose, sucrose, fructose etc
Which are reducing sugars?
What happens to the Benedicts solution with reducing sugars and why?
Which chemical group do these reducing sugars have?
3. a) What are the names of the molecules responsible for the smell of garlic and the tear inducing properties of onions.
b) Which non-metallic elements do both these chemicals contain?
c) What are the supposed advantages and obvious disadvantage of
eating garlic?
4. a) Survey a range of foods to find the % sodium chloride content.
b) What other reason(s) is salt added to food other than for flavouring.?