Displacement reactions take place between metals and metal ions.
They can be used to work out the reactivity order of metals such as lead (Pb), nickel (Ni), and silver (Ag).
The ionic equation for a displacement reaction is shown.
$\text{Ni(s)} + \text{Pb}^{2+}\text{(aq)} \rightarrow \text{Pb(s)} + \text{Ni}^{2+}\text{(aq)}$
The ionic half-equations for this reaction are shown.
$\text{Ni(s)} \rightarrow \text{Ni}^{2+}\text{(aq)} + 2e^-$
$\text{Pb}^{2+}\text{(aq)} + 2e^- \rightarrow \text{Pb(s)}$
These ionic half-equations show nickel atoms donating electrons and lead ions accepting them.
(a(i))[2]
Identify the reducing agent in the displacement reaction. Give a reason for your choice.
(a(ii))[1]
What general name is given to a reaction in which electrons are transferred from one species to another?
(b)[2]
Write out the two ionic half-equations for this reaction.
(c)[1]
Arrange lead, nickel and silver from the most reactive to the least reactive.
(d)[2]
Describe two other differences in the physical properties of nickel and sodium.
(e)[1]
Predict one difference in the appearance of aqueous nickel-compound solutions compared with aqueous sodium-compound solutions.
(f(i))[3]
Fill in the box labels.
(f(ii))[1]
Mark N on the diagram to show the position where nickel is produced.
Worked solution & mark scheme
This 13-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Ni, that is nickel” …