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Read the text below and answer the questions that follow - NSC Marine Sciences - Question 2 - 2023 - Paper 1
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Read the text below and answer the questions that follow. The search for a cleaner source of harvesting electrical energy has made headlines for a while. More atten... show full transcript
Worked Solution & Example Answer:Read the text below and answer the questions that follow - NSC Marine Sciences - Question 2 - 2023 - Paper 1
Step 1
Step 2
2.1.2 Give a hypothesis for the investigation.
Answer
As the salinity of the solution increases, the average volume of hydrogen captured during electrolysis will also increase. This is based on the assumption that higher salt concentrations facilitate more efficient electrolysis, resulting in greater hydrogen production.
Step 3
2.1.3 Draw a line graph to show the average volume of hydrogen captured during electrolysis for different salinities of water.
Answer
To draw the line graph:
- Title: Salinity vs Average Volume of Hydrogen Captured
- X-axis: Salinity (ppt), labeled appropriately
- Y-axis: Average Volume of Hydrogen Captured (ml/min), labeled appropriately
- Plot the points for each solution and connect them with a line to show the trend. Ensure to label key values on both axes clearly.
Step 4
2.1.4 Based on the results of this study, describe the relationship between the salinity and the volume of hydrogen captured.
Answer
The relationship between the salinity and the volume of hydrogen captured is positively correlated. As the salinity of the solution increases, the average volume of hydrogen captured during electrolysis also increases. This suggests that higher concentrations of salt contribute to a more efficient electrolysis process, resulting in greater hydrogen production.
Step 5
2.1.5 Discuss the molecular structure of a water molecule.
Answer
A water molecule (H₂O) consists of two hydrogen atoms covalently bonded to one oxygen atom. The oxygen atom is more electronegative than hydrogen, creating a polar molecule with a bent shape. This polarity allows water to be an excellent solvent and facilitates the electrolysis process, where water dissociates into hydrogen and oxygen gases.
Step 6
2.1.6 Why would it be beneficial to use sea water instead of freshwater as an alternative source of energy?
Answer
Using seawater instead of freshwater for energy production is beneficial because:
- Sea water is abundant and more readily available compared to freshwater, which is a limited resource.
- Utilizing seawater can help manage and mitigate the impact of increasing salinity in freshwater systems as we shift towards alternative energy sources.
Step 7
2.1.7 In your opinion, is electrolysis of salt water a sustainable alternative to clean energy? Give TWO reasons to support your answer.
Answer
Yes, electrolysis of salt water can be considered a sustainable alternative to clean energy for several reasons:
- It utilizes a renewable resource (sea water) that is abundant and available worldwide, reducing the reliance on freshwater supplies.
- The process produces hydrogen, which can be used as a clean fuel, emitting only water vapor when consumed in fuel cells, thus contributing to lower greenhouse gas emissions.