On the diagram below, draw a clear labelled sketch that shows the shape and symmetry of a typical d-orbital.
Draw an orbital energy diagram for this, showing how many orbitals are in each group.
Use your diagram to help explain the following. Transition element complexes are often coloured. The colour of a complex of a particular transition element often changes if the ligands around it are altered.
Calculate the oxidation number for carbon in this ion.
Calculate the oxidation number of iron for $[\text{Fe(C}_2\text{O}_4)_3]^{3-}$.
In the ion $[\text{Fe(C}_2\text{O}_4)_3]^{3-}$, the iron atom is octahedrally surrounded by six oxygen atoms. Complete the displayed formula of this ion below.
In sunlight, the complex breaks down into potassium ethanedioate, iron(II) ethanedioate and carbon dioxide. Use oxidation numbers to help you balance the following equation for this decomposition. $\text{K}_3\text{Fe(C}_2\text{O}_4)_3 \rightarrow \ldots\ldots\ldots\text{K}_2\text{C}_2\text{O}_4 + \ldots\ldots\ldots\text{FeC}_2\text{O}_4 + \ldots\ldots\ldots\text{CO}_2$