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A student investigated how temperature affects the rate of reaction between magnesium carbonate and dilute hydrochloric acid - AQA - GCSE Chemistry - Question 8 - 2018 - Paper 2
Question 8
A student investigated how temperature affects the rate of reaction between magnesium carbonate and dilute hydrochloric acid. This is the method used. 1. Heat hydr... show full transcript
Worked Solution & Example Answer:A student investigated how temperature affects the rate of reaction between magnesium carbonate and dilute hydrochloric acid - AQA - GCSE Chemistry - Question 8 - 2018 - Paper 2
Step 1
Explain why the contents of the conical flask lose mass.
Answer
When magnesium carbonate reacts with hydrochloric acid, a gas is produced (specifically carbon dioxide). This gas escapes into the surrounding environment, leading to a measurable loss in mass of the conical flask and its contents.
Step 2
Plot the data from Table 5 on Figure 6.
Answer
To plot the data, mark each pair of values from Table 5 on Figure 6. The x-axis represents 'Time in seconds' and the y-axis represents 'Loss of mass in grams'. Ensure all eight points are plotted accurately, using a tolerance of ± half a small square if necessary. Draw a line of best fit that represents the trend of the data.
Step 3
Determine the rate of reaction at 50 °C when the loss of mass is 0.95 g.
Answer
To determine the rate of reaction, first draw a tangent line at the point where the loss of mass reaches 0.95 g on Figure 7. Use two distinct points on this tangent line to calculate the slope. The slope is calculated as follows:
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Identify the points on the tangent line, for example, (x1, y1) and (x2, y2).
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The rate of reaction is given by:
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Substitute the y-values (loss of mass) and x-values (time) from the points identified.
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Provide the final answer rounded to 2 significant figures.