Sodium chromate(VI), $\text{Na}_2\text{CrO}_4$, is produced by strongly heating chromite, $\text{FeCr}_2\text{O}_4$, together with sodium carbonate in an oxidising atmosphere. Chromite contains $\text{Cr}_2\text{O}_4^{2-}$ ions. $2\text{FeCr}_2\text{O}_4 + 4\text{Na}_2\text{CO}_3 + 3\tfrac{1}{2}\text{O}_2 \rightarrow 4\text{Na}_2\text{CrO}_4 + \text{Fe}_2\text{O}_3 + 4\text{CO}_2$ What is happening in this reaction?
- AChromium and iron are the only elements oxidised.
- BChromium, iron and carbon are oxidised.
- COnly chromium is oxidised.
- DOnly iron is oxidised.