Zusammenfassung der Ressource
Frage 1
Frage
True or false? Using hard water makes it more difficult for soap to lather.
Frage 2
Frage
Which of these rocks helps to cause hardness in water?
Antworten
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Gypsum
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Granite
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Dolomite
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Calcite
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Basalt
Frage 3
Frage
Which type of deposit forms when hard water reacts with soap?
Antworten
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Scale, calcium carbonate
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Scum, calcium stearate
Frage 4
Frage
Which type of deposit forms when hard water is boiled?
Antworten
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Scale, calcium carbonate
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Scum, calcium stearate
Frage 5
Frage
True or false? Calcium carbonate dissolves in carbonic acid (rainwater) to produce calcium ions and hydrogencarbonate ions.
Frage 6
Frage
Which type of hard water can be softened by heating?
Antworten
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Permanent hard water
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Temporary hard water
Frage 7
Frage
True or false? Scale is formed upon heating temporary hard water because calcium hydrogencarbonate forms a precipitate.
Frage 8
Frage
Which of these methods can soften either type of hard water?
Antworten
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Washing soda
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Boiling
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Ion-exchange column
Frage 9
Frage
Which ion is exchanged with calcium and magnesium ions in an ion-exchange column?
Antworten
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Potassium K+
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Sodium Na+
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Cadmium Cd2+
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Iron Fe3+
Frage 10
Frage
True or false? Ion-exchange columns do not need to be regularly washed out with saline solution.
Frage 11
Frage
What is the first stage in the water treatment process?
Antworten
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Passing water through a sand filter for clear water
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Passing water through metal meshes to remove large objects
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Chlorination of water to kill bacteria
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Adding aluminium sulphate and lime to encourage flocculation of suspended particles in the water
Frage 12
Frage
What is the second stage in the water treatment process?
Antworten
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Passing water through a sand filter for clear water
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Passing water through metal meshes to remove large objects
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Chlorination of water to kill bacteria
-
Adding aluminium sulphate and lime to encourage flocculation of suspended particles in the water
Frage 13
Frage
What is the third stage in the water treatment process?
Antworten
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Passing water through a sand filter for clear water
-
Passing water through metal meshes to remove large objects
-
Chlorination of water to kill bacteria
-
Adding aluminium sulphate and lime to encourage flocculation of suspended particles in the water
Frage 14
Frage
What is the fourth stage in the water treatment process?
Antworten
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Passing water through a sand filter for clear water
-
Passing water through metal meshes to remove large objects
-
Chlorination of water to kill bacteria
-
Adding aluminium sulphate and lime to encourage flocculation of suspended particles in the water
Frage 15
Frage
What is often contained in a filter cartridge?
Antworten
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Activated carbon
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Activated boron
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Ion-exchange column
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Fractionating column
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Silver
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Ruthenium
Frage 16
Frage
What are health benefits of drinking hard water?
Frage 17
Frage
Which gas is sometimes used as an alternative to chlorine in killing bacteria?
Antworten
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Fluorine
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Hydrogen sulphide
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Ozone
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Methane
Frage 18
Frage
Which ion is sometimes added to water to reduce the risk of tooth decay?
Antworten
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Sulphate, SO42-
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Fluoride, F-
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Nitrate, NO3-
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Potassium, K+
Frage 19
Frage
Which of these are arguments for the fluoridation of water?
Antworten
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Reduction in tooth decay
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Increased risk of fluorosis
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Protects people who don't have good dental hygiene
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Impossible to set safe limits due to varied intake
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Ethical issues of being forced to take a treatment
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Reduced risk of heart disease
Frage 20
Frage
Which of these are arguments against the fluoridation of water?
Antworten
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Reduction in tooth decay
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Increased risk of fluorosis
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Protects people who do not have good dental hygiene
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Impossible to set safe limits due to varied intake
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Ethical issues with being forced to take a treatment
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Reduced risk of heart disease