Dissolved compounds such as calcium and magnesium salts.
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What happens when the calcium and/or magnesium ions in hard water react with soap?
They produce a precipitate called scum.
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What can temporary hard water produce when heated?
A solid scale.
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What effect does scale have on appliances?
It can be deposited in kettles, boilers and pipes and it reduces the efficiency of kettles and heating systems and can cause blockages.
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Which has more benefits to health, hard water or soft water?
Hard water.
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Why is hard water more beneficial to health than soft water?
It may contain calcium compounds which are good for developing and maintaining teeth and bones, and may also help to prevent heart disease.
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What type of water lathers easily with soap?
Soft water.
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Why does soft water lather more easily with soap than hard water?
Hard water uses more soap to lather than soft water because it contains dissolved compounds that react with soap to form an insoluble solid called scum.
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What are soapless detergents?
Detergents that do not react with hard water to form scum.
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What is the difference between soft water and hard water?
Soft water lathers easily with only a little soap whereas hard water uses more soap and produces scum.
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What happens when water is in contact with rocks?
Some compounds dissolve, if the water contains dissolved calcium or magnesium ions, these will react with soap to form scum and so the water is hard.
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What type of water produces scale when heated?
Temporary hard water.
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What is the difference between scum and scale?
Scum is formed when soap reacts with compounds in hard water whereas scale is produced when temporary hard water is heated or boiled.
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Why is it better to drink hard water rather than soft water?
Hard water contains calcium compounds that are good for health, for the development of bones and teeth, and to reduce the risk of heart disease.
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Other cards in this set
Card 2
Front
What happens when the calcium and/or magnesium ions in hard water react with soap?
Back
They produce a precipitate called scum.
Card 3
Front
What can temporary hard water produce when heated?
Back
Card 4
Front
What effect does scale have on appliances?
Back
Card 5
Front
Which has more benefits to health, hard water or soft water?
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