A student investigated the temperature change in the reaction between dilute sulfuric acid and potassium hydroxide solution - AQA - GCSE Chemistry - Question 9 - 2019 - Paper 1
Question 9
A student investigated the temperature change in the reaction between dilute sulfuric acid and potassium hydroxide solution.
This is the method used.
1. Measure 25... show full transcript
Worked Solution & Example Answer:A student investigated the temperature change in the reaction between dilute sulfuric acid and potassium hydroxide solution - AQA - GCSE Chemistry - Question 9 - 2019 - Paper 1
Step 1
Suggest why the student used a polystyrene cup rather than a glass beaker for the reaction.
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Answer
Polystyrene is a better thermal insulator compared to glass. It reduces energy exchange with the surroundings, minimizing heat loss during the exothermic reaction.
Step 2
Complete Figure 11: plot the data from Table 6.
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Answer
Plot all six points from Table 6 on the graph. Ensure accuracy by allowing for a tolerance of ± ½ a small square for each point. Then, draw lines of best fit through the plotted points, extending the lines until they intersect.
Step 3
Determine the volume of dilute sulfuric acid needed to react completely with 25.0 cm³ of the potassium hydroxide solution.
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Answer
Refer to Figure 11 to find the volume where the line indicating the temperature change intersects. Based on the data, the volume of dilute sulfuric acid needed to react completely should be around 11 cm³.
Step 4
Determine the overall temperature change when the reaction is complete.
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Answer
Calculate the overall temperature change as follows:
Overall temperature change = final temperature - initial temperature = 27.0°C - 18.9°C = 8.1°C.
