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Question 1
This question is about water. |
a) | Explain what is meant by the term potable water.
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b) | Explain how potable water can be produced from fresh water.
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c) | It is also possible to produce potable water from seawater. Suggest a method you might use to obtain potable water from seawater.
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d) | Discuss one disadvantage of using distillation to obtain potable water.
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Question 2
This question is about the processing of water to create potable water. |
a) | Describe the role of filter beds in the filtration process.
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b) | After water has been filtered it needs to be sterilised. Explain how and why the water needs to be sterilised.
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c) | State the name of the substance removed from seawater by desalination.
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d) | Potable water is not the same as pure water. Explain the difference between potable water and pure water.
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Question 3
A student has a sample of dirty, undrinkable water. The student wants to turn the dirty water into potable water. |
a) | Describe how the student could remove undissolved solids from the water.
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b) | Describe how the student could obtain potable water from the water obtained in part a).
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c) | The sample of water contains 14 g/dm3 of dissolved solids. Calculate the mass of dissolved solids present in the 150 cm3 sample. Give your answer in grams, and to 1 decimal places.
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Question 4
This question is about safe drinking water. |
a) | State the scientific term given to safe drinking water.
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b) | A student has a sample of water which they think is safe to drink. Describe how the student could test the pH of the water, and what results would suggest the water is potable.
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c) | The student records a pH of 7.2 for the sample of water. Describe the two other criteria for the water to be considered potable.
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d) | The student isn't sure if the sample contains bacteria. Describe how the student could make water that contains bacteria safe to drink.
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Question 5
This question is about the processing of waste water. |
a) | The processes and descriptions below outline the stages of processing waste water. Match the statements to their purpose.
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b) | Suggest one use for the solid sewage removed from the waste water.
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c) | Suggest one reason why the total mass of solid sewage processed increased between 2010 and 2020.
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Question 6
This question is about the processing of waste water. |
a) | Which of the following is the purpose of screening waste water? A to sterilise the water B to remove dissolved solids C to kill harmful micro-organisms D to remove large solid objects
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b) | How is liquid effluent processed in a waste treatment works? A screening B aerobic biological treatment C anaerobic digestion D sedimentation
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c) | How is waste water sterilised in the final stage of treatment? A water is distilled B water is filtered C water has chlorine added D water is screened
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d) | Which of the following describes how solid sewage sludge is processed? A aerobic biological treatment B anaerobic digestion C sedimentation D screening
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