A cleaned pure copper strip, Cu(s), is placed in a beaker containing a colourless silver nitrate solution, AgNO3(aq), at 25 °C, as shown below - NSC Physical Sciences - Question 8 - 2023 - Paper 2
Question 8
A cleaned pure copper strip, Cu(s), is placed in a beaker containing a colourless silver nitrate solution, AgNO3(aq), at 25 °C, as shown below.
After a while, it is... show full transcript
Worked Solution & Example Answer:A cleaned pure copper strip, Cu(s), is placed in a beaker containing a colourless silver nitrate solution, AgNO3(aq), at 25 °C, as shown below - NSC Physical Sciences - Question 8 - 2023 - Paper 2
Step 1
8.1.1 ONE other OBSERVABLE change, besides the solution turning blue.
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Answer
The copper strip becomes thinner or corrodes, indicating that it is losing mass due to the deposition of silver on the surface.
Step 2
8.1.2 the NAME or FORMULA of the oxidising agent.
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Answer
The oxidising agent is Ag⁺ (silver ion).
Step 3
8.2 Explain the answer to QUESTION 8.1.1 by referring to the relative strengths of the oxidising agents or reducing agents.
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Answer
Ag⁺ is a stronger oxidising agent than Cu²⁺ ions. Therefore, Ag⁺ ions will oxidise Cu to Cu²⁺, causing the observable changes, such as the thinning of the copper strip.
Step 4
8.3.1 NAME or FORMULA of electrode A.
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Answer
Electrode A is the copper (Cu) electrode.
Step 5
8.3.2 NAME or FORMULA of solution B.
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Answer
Solution B is silver nitrate (AgNO₃).
Step 6
8.3.3 Overall (net) balanced equation for the cell reaction.
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Answer
The overall balanced equation for the cell reaction can be represented as:
2Ag+(aq)+Cu(s)→2Ag(s)+Cu2+(aq)
Step 7
8.4 Write down the FORMULA of the ion in the salt bridge that will move into the silver in solution from K⁺(aq) or NO3⁻(aq).
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Answer
The ion in the salt bridge that will move into the silver in solution is NO₃⁻ (nitrate ion).
Step 8
Give a reason for the answer.
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Answer
The nitrate ion is negatively charged and will balance out the positive charges of the Ag⁺ ions in the solution, maintaining electrical neutrality.
