Chemistry · BGCSE / Air, water and the environment
StructuredPast exam questionForm 5 · BGCSE
A sample of water from a limestone area needed a large quantity of soap to form lather. After heating, the same amount of the sample formed lather easily with a very small quantity of soap.
- aName a compound which caused the hardness in the sample of water. [1]
- bExplain why hard water does not lather easily. [1]
- cExplain why after heating the sample, lather was formed with a very small quantity of soap. Include an equation. [4]
- dDescribe how the compound which causes the hardness gets into this water. [2]
You'll mark your own answer against the marking guide when you hand it in.
Source: BEC BGCSE Chemistry 2008, Paper 3, Question 6
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