A student investigated the reaction between magnesium and excess hydrochloric acid - AQA - GCSE Chemistry Combined Science - Question 1 - 2021 - Paper 2
Question 1
A student investigated the reaction between magnesium and excess hydrochloric acid. Figure 1 shows the apparatus.
This is the method used.
1. Pour 50 cm³ of hydroch... show full transcript
Worked Solution & Example Answer:A student investigated the reaction between magnesium and excess hydrochloric acid - AQA - GCSE Chemistry Combined Science - Question 1 - 2021 - Paper 2
Step 1
Give the independent variable and one control variable in this investigation.
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Answer
Independent variable: concentration of hydrochloric acid.
Control variable: any one from:
temperature of hydrochloric acid
volume of hydrochloric acid
length of magnesium
surface area of magnesium.
Step 2
Complete Figure 2.
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Answer
To complete Figure 2, plot the points from Table 1 onto the graph, ensuring to mark the volumes of gas against the corresponding times in seconds. Draw a line of best fit through the points, making sure that the line starts at (0,0). The graph should show the volume of gas increasing over time.
Step 3
How does the rate of this reaction change with time?
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Answer
The rate decreases.
Step 4
Which statement is correct?
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Answer
The magnesium reacted more quickly.
Step 5
Explain how increasing the temperature affects the rate of the reaction.
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Answer
Increasing the temperature increases the energy of the particles. As the particles gain more energy, they move faster. This results in more frequent collisions between the reactant particles. More collisions lead to a higher likelihood of successful reactions, thereby increasing the overall rate of the reaction.
