Silver electroplating of steel objects is carried out in three stages.
step 1 A layer of copper is deposited on the object.
step 2 A layer of nickel is deposited on the object.
step 3 A layer of silver is deposited on the object.
(a(i))[1]
The reaction occurring on the object’s surface is $\text{Cu}^{2+}(aq) + 2e^- \rightarrow \text{Cu}(s)$. Explain whether this surface reaction is oxidation or reduction.
(a(ii))[2]
Explain why the concentration of copper ions in the electrolyte stays constant throughout step 1.
(b)[2]
Give two changes which would be required in order to coat nickel onto the object in step 2.
(c)[3]
Give three separate properties of transition metals that are not usually characteristic of other metals.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “reduction: Cu^{2+} gains electrons / oxidation number decreases” …