State the overall redox equation when carbon monoxide reduces Fe₂O₃ to Fe.

Predict the magnetic properties of Fe₂O₃ and Al₂O₃ in terms of the electron structure of the metal ion, giving your reasons.

Fe₂O₃:

Al₂O₃:
 

Molten alumina, Al₂O₃(l), was electrolysed by passing 2.00×10⁶ C through the cell. Calculate the mass of aluminium produced, using sections 2 and 6 of the data booklet.

Fe₂O₃ (s) + 3CO (g) → 2Fe (l) + 3CO₂ (g)

Fe₂O₃:
paramagnetic
AND
unpaired electrons present «so magnetic moments do not cancel out»

Al₂O₃:
diamagnetic
AND
no unpaired electrons/all electrons are paired «so magnetic moments cancel out»

Award [1 max] for “Fe₂O₃ paramagnetic AND Al₂O₃ diamagnetic”.

Award [1 max] for “Fe₂O₃ unpaired electrons present AND Al₂O₃ no unpaired electrons/all electrons are paired”.

Award [1 max] for “Magnetic moments do not cancel out in Fe₂O₃ but do in Al₂O₃”.

Unpaired and paired electrons may also be conveyed by orbital diagrams for the respective ions.

\(n\left( {\rm{e}} \right) = \frac{{2.00 \times {{10}^6}}}{{96500}}/20.7 \ll {\rm{mol}} \gg \)

OR
n(Al)=\(\frac{1}{3}\)n(e)/6.91«mol»

m(Al)=«6.91×26.98=»186«g»

Award [2] for correct final answer for any value within the range 186–189 «g».