Define the term transition element.
In an isolated gaseous $\text{Cu}^{2+}$ ion, the 3d orbitals are degenerate. Define the term degenerate.
Complete the electronic configuration of $\text{Cu}^{2+}$. $1s^2$ ...
State the colours of the aqueous solutions for the two copper(II) complex ions shown: $[\text{Cu}(\text{NH}_3)_4(\text{H}_2\text{O})_2]^{2+}(\text{aq})$ and $[\text{CuCl}_4]^{2-}(\text{aq})$.
Explain why aqueous complex ions of transition elements are usually coloured.
If excess $\text{NH}_3(\text{aq})$ is added to a solution of $[\text{CuCl}_4]^{2-}(\text{aq})$, $[\text{Cu}(\text{NH}_3)_4(\text{H}_2\text{O})_2]^{2+}(\text{aq})$ is produced. State the type of reaction. Complete the equation for this reaction. State symbols are not required. $[\text{CuCl}_4]^{2-} + \ldots \rightarrow [\text{Cu}(\text{NH}_3)_4(\text{H}_2\text{O})_2]^{2+} + \ldots$
The $[\text{Cu}(\text{NH}_3)_4(\text{H}_2\text{O})_2]^{2+}$ complex ion shows stereoisomerism. Complete the three-dimensional diagrams in Fig. 1.1 to show the two different stereoisomers of $[\text{Cu}(\text{NH}_3)_4(\text{H}_2\text{O})_2]^{2+}$.
Deduce which stereoisomer in (d)(ii) is polar. Explain your answer.
The dianion $P$ can act as a tridentate ligand. Suggest how $P$ can form three dative covalent bonds.
$2$ moles of dianion $P$, $\text{C}_4\text{H}_5\text{NO}_4^{2-}$, react with $1$ mole of aqueous cobalt(III) ions, $[\text{Co}(\text{H}_2\text{O})_6]^{3+}$, to form $1$ mole of complex ion $Q$. Deduce the formula and charge of $Q$.
Define the stability constant of a complex.
Use the information in Table 1.1 to identify the most stable silver(I) complex. Explain your answer.
A $3.75\,\mathrm{g}$ sample of impure $\mathrm{Na_2SO_3}$ is dissolved in distilled water and then made up to $250\,\mathrm{cm^3}$ in a volumetric flask. A $10.0\,\mathrm{cm^3}$ portion needs $18.70\,\mathrm{cm^3}$ of acidified $0.0150\,\mathrm{mol\,dm^{-3}}\;\mathrm{MnO_4^-}(\mathrm{aq})$ to reach the end-point. The reaction is given by: $2\mathrm{MnO_4^-} + 5\mathrm{SO_3^{2-}} + 6\mathrm{H^+} \rightarrow 2\mathrm{Mn^{2+}} + 5\mathrm{SO_4^{2-}} + 3\mathrm{H_2O}$. Calculate the percentage by mass of $\mathrm{Na_2SO_3}$ in the sample.