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This question is about water - AQA - GCSE Chemistry - Question 2 - 2020 - Paper 2
Question 2
This question is about water. In the UK, potable (drinking) water is produced from different sources of fresh water. Explain how potable water is produced from fres... show full transcript
Worked Solution & Example Answer:This question is about water - AQA - GCSE Chemistry - Question 2 - 2020 - Paper 2
Step 1
Explain how potable water is produced from fresh water.
Answer
Potable water in the UK is produced through several key steps. First, appropriate sources of fresh water such as rivers, streams, lakes, or boreholes are chosen. The collected water then passes through filter beds, which remove undissolved solids, ensuring clarity. After filtration, the water is sterilized using methods like chlorine treatment or ultraviolet (UV) light to eliminate harmful microbes, making the water safe for drinking.
Step 2
Suggest one process this country could use to obtain most of its potable water.
Answer
The country could utilize desalination, a process that removes salts and impurities from seawater, making it suitable for potable use. This is especially effective given its long coastline and plentiful energy supplies.
Step 3
Step 4
Calculate the percentage of processed solid sewage sludge that was burned in 2010.
Answer
To find the percentage of processed solid sewage sludge that was burned in 2010, we use the formula:
ext{Percentage} = rac{ ext{Mass burned}}{ ext{Total mass}} imes 100
Substituting the values from Table 1:
ext{Percentage} = rac{260}{1413} imes 100 \\ = 18.39 \approx 18.4 \%
Step 5
Suggest one reason why the total mass of processed solid sewage sludge increased between 1992 and 2010.
Answer
One reason for the increase in total mass of processed solid sewage sludge could be an increase in population, leading to more waste water being produced and therefore more sewage sludge generated.
Step 6
Suggest two reasons why the proportion of processed solid sewage sludge used as fertiliser increased.
Answer
- Increased demand for food due to the growing population has led to more farming, resulting in higher usage of sewage sludge as a fertiliser.
- Greater awareness of the environmental impacts of waste disposal has motivated the use of processed sewage sludge as an organic fertiliser, which conserves resources and promotes sustainability.