QUESTION 9 (Start on a new page.)
The diagram below represents a simplified cell used for the electrolysis of CONCENTRATED chromium(III) chloride, CrCl₃(aq) - NSC Physical Sciences - Question 9 - 2022 - Paper 2
Question 9
QUESTION 9 (Start on a new page.)
The diagram below represents a simplified cell used for the electrolysis of CONCENTRATED chromium(III) chloride, CrCl₃(aq). Electr... show full transcript
Worked Solution & Example Answer:QUESTION 9 (Start on a new page.)
The diagram below represents a simplified cell used for the electrolysis of CONCENTRATED chromium(III) chloride, CrCl₃(aq) - NSC Physical Sciences - Question 9 - 2022 - Paper 2
Step 1
Define the term electrolysis.
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Answer
Electrolysis is the chemical process in which electrical energy is converted to chemical energy. It occurs during the passage of an electric current through a solution or molten ionic compound.
Step 2
Write down the half-reaction that takes place at electrode T.
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Answer
The half-reaction at electrode T, where oxidation occurs, is:
ightarrow ext{Cl}_2(g) + 2e^-$$
Step 3
Calculate the total charge that flows through the cell during this time.
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Answer
To calculate the total charge (Q) that flows through the cell, we use the formula:
Q=Iimest
Where:
I = current (2.5 A)
t = time in seconds (10 hours = 10 x 60 x 60 = 36,000 seconds)
Thus, substituting the values:
Q=2.5imes36000=90,000extC
Step 4
Value of X as shown on the graph.
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Answer
To find the value of X represented on the graph, we analyze the mass change corresponding to time and total charge to determine the mass loss of electrode T after 10 hours.
Using the relationship derived from the total charge and stoichiometry of the reaction, we can calculate the mass change, which will provide the value of X.
