(a)[2]
Calculate the mass of copper present in $20.0$ tonnes of $\text{CuFeS}_2$.
(b)[2]
When $\text{CuFeS}_2$ is heated in air, copper(II) oxide, iron(III) oxide and sulfur dioxide are produced. Construct the equation for this reaction.
(c)[1]
Heating copper(II) oxide with carbon reduces it to copper. Construct the equation for this reaction.
(d(i))[1]
Identify the electrolyte employed to purify impure copper by electrolysis.
(d(ii))[2]
What are the electrodes made of? State the positive electrode (anode) and the negative electrode (cathode).
(d(iii))[2]
Write the half-equations for the reactions taking place at both electrodes.