This is about electrolysis - AQA - GCSE Chemistry Combined Science - Question 1 - 2018 - Paper 1
Question 1
This is about electrolysis.
A student investigates the mass of copper produced during electrolysis of copper chloride solution.
Figure 1 shows the apparatus.
Which ... show full transcript
Worked Solution & Example Answer:This is about electrolysis - AQA - GCSE Chemistry Combined Science - Question 1 - 2018 - Paper 1
Step 1
Which gas is produced at the positive electrode (anode)?
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Answer
The gas produced at the positive electrode is chlorine.
Step 2
Copper is produced at the negative electrode (cathode). What does this tell you about the reactivity of copper?
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Answer
This indicates that copper is less reactive than hydrogen.
Step 3
Determine the mean mass of copper produced after 3 minutes.
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Answer
To find the mean mass of copper produced after 3 minutes, sum the results from Experiment 1, Experiment 2, and Experiment 3. Thus:
ext{Mean} = rac{2.40 + 2.41 + 2.39}{3} = 2.40 ext{ mg}
Therefore, the mean mass is 2.40 mg.
Step 4
Calculate the mass X of copper produced in Experiment 2 after 5 minutes.
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Answer
From Table 1, the mean mass of copper produced after 5 minutes can be calculated as:
X=3.02+3.01+3.06/3=3.03extmg
Thus, Mass X = 3.03 mg.
Step 5
Calculate the mass of solid copper chloride used in each experiment.
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Answer
Given that the copper chloride solution contains 300 grams per dm³ and 50 cm³ was used in each experiment:
First, convert 50 cm³ to dm³:
50extcm3=0.05extdm3
Now, calculate the mass:
extMass=300extg/dm3imes0.05extdm3=15extg
Therefore, the mass of solid copper chloride used in each experiment is 15 g.
