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Titan is a moon of the planet Saturn - AQA - GCSE Chemistry - Question 8 - 2019 - Paper 2
Question 8
Titan is a moon of the planet Saturn. Table 3 shows the percentages of the gases in the atmosphere of Titan. Table 3 Gas Percentage of gas in atmosphere (%) Ni... show full transcript
Worked Solution & Example Answer:Titan is a moon of the planet Saturn - AQA - GCSE Chemistry - Question 8 - 2019 - Paper 2
Step 1
Explain why these organisms could not have evolved in the same way that life is thought to have evolved on Earth.
Answer
The evolution of organisms on Earth is largely dependent on oxygen, which is necessary for processes like photosynthesis. On Titan, it is believed that there is little to no oxygen available. Therefore, photosynthesis cannot occur as it does on Earth, leading to the conclusion that carbon dioxide, which is required for photosynthesis, is also scarce. Consequently, oxygen-using organisms could not have evolved on Titan.
Step 2
Explain how this greenhouse gas keeps Titan warmer than the other moons of Saturn.
Answer
Methane in Titan's atmosphere plays a crucial role in retaining heat. It allows short-wavelength radiation from the sun to penetrate the atmosphere and reach Titan's surface. However, when this energy is re-emitted from the surface, it is in the form of longer-wavelength infrared radiation. Methane absorbs this longer-wavelength radiation, trapping heat in the atmosphere and preventing it from escaping, which results in a warmer environment compared to other moons of Saturn.
Step 3
Describe a test to show that propene is an unsaturated hydrocarbon.
Answer
To test for the unsaturation of propene, bromine water can be used. When propene is added to bromine water, the solution will change from brown to colourless, indicating that the double bond in the propene reacts with bromine, thus proving it is an unsaturated hydrocarbon.