Question

Which of the following reactions is an example of auto reduction?

Options

• \[\ce{Fe3O4 + 4CO -> 3Fe + 4CO2}\]

• \[\ce{Cu2O + C -> 2Cu + CO}\]

• \[\ce{Cu2 + (aq) + Fe(S) -> Cu(S) + Fe2 + (aq)}\]

• \[\ce{Cu2O + 1/2 Cu2S -> 3Cu + 1/2 SO2}\]

Answer 1

\[\ce{Cu2O + 1/2 Cu2S -> 3Cu + 1/2 SO2}\]

Explanation:

Cu₂O is reduced to cu, where as Cu₂S is oxidised to SO₂.