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The concentration of carbon dioxide (CO₂) in the Earth's atmosphere has been increasing steadily since the mid nineteenth century - VCE - SSCE Chemistry - Question 5 - 2002 - Paper 1
Question 5
The concentration of carbon dioxide (CO₂) in the Earth's atmosphere has been increasing steadily since the mid nineteenth century. This is due mainly to the increase... show full transcript
Worked Solution & Example Answer:The concentration of carbon dioxide (CO₂) in the Earth's atmosphere has been increasing steadily since the mid nineteenth century - VCE - SSCE Chemistry - Question 5 - 2002 - Paper 1
Step 1
i. Name one factor, other than the heat of combustion, that should be considered when selecting a fuel for a particular purpose.
Answer
When selecting a fuel for a particular purpose, one important factor to consider is the energy content of the fuel. This refers to the amount of energy produced per unit mass or volume of the fuel, which affects efficiency and overall performance.
Step 2
ii. The burning of fossil fuels is associated with other undesirable emissions besides CO₂. Give two other undesirable atmospheric pollutants directly or indirectly caused by the burning of fossil fuels.
Answer
Two other undesirable atmospheric pollutants caused by the burning of fossil fuels are:
- Sulfur dioxide (SO₂) - which can contribute to acid rain.
- Nitrogen oxides (NOₓ) - which can lead to smog formation and respiratory problems.
Step 3
1. Identify one advantage (other than the non-emission of CO₂) and one disadvantage in relation to its suitability as a substitute for the current uses of fossil fuels.
Answer
Non-fossil fuel alternative: Nuclear Advantage: Nuclear power can provide major energy without the emissions of greenhouse gases. Disadvantage: The disposal of radioactive waste presents a significant environmental risk.
Step 4
2. Identify one advantage (other than the non-emission of CO₂) and one disadvantage in relation to its suitability as a substitute for the current uses of fossil fuels.
Answer
Non-fossil fuel alternative: Solar Advantage: Solar energy is renewable and has low operational costs once the infrastructure is in place. Disadvantage: Solar energy production is dependent on weather conditions, leading to variability in energy supply.
Step 5
Step 6
ii. What is the source of the energy released when ²³⁸U undergoes fission?
Answer
The energy released during the fission of ²³⁸U comes primarily from the conversion of mass into energy, as described by Einstein's equation, . This energy is generated as new atoms are formed and kinetic energy from the released neutrons occurs.