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The table shows the percentage yield of methane in the equilibrium mixture under different conditions - OCR Gateway - GCSE Chemistry - Question 21 - 2019 - Paper 2
Question 21
The table shows the percentage yield of methane in the equilibrium mixture under different conditions. | Pressure (in atmospheres) | 100 | 200 | 300 | 400 | |------... show full transcript
Worked Solution & Example Answer:The table shows the percentage yield of methane in the equilibrium mixture under different conditions - OCR Gateway - GCSE Chemistry - Question 21 - 2019 - Paper 2
Step 1
Describe what happens to the percentage yield as the pressure changes.
Answer
As seen in the table, the percentage yield of methane increases with an increase in pressure. For instance, at a temperature of 300°C, the yield rises from 35% at 100 atmospheres to 80% at 400 atmospheres. This trend indicates that higher pressure favors the production of methane.
Step 2
Describe what happens to the percentage yield as the temperature changes.
Answer
The yield of methane varies with temperature as well. At lower temperatures, such as 300°C, the yield is higher compared to higher temperatures. For example, at a temperature of 1200°C and 400 atmospheres, the yield drops to 48%. This suggests that lower temperatures favor the formation of methane in this reaction.
Step 3
Explain the effect of increasing the pressure on the rate of reaction.
Answer
Increasing the pressure typically increases the rate of reaction, particularly in reactions involving gases. This is because higher pressure results in a greater concentration of gas molecules, which leads to more frequent collisions between reactant molecules. Thus, as the pressure increases, the rate of reaction may increase, leading to a higher yield of the desired product.