Complete the electronic configurations for the copper atom and the copper ion in the $+2$ oxidation state.
An equilibrium is set up between two copper complex ions in the $+2$ oxidation state: $[\text{Cu(H}_2\text{O})_6]^{2+} + 4\text{Cl}^- \rightleftharpoons [\text{CuCl}_4]^{2-} + 6\text{H}_2\text{O}$. Name the type of reaction taking place here.
State the colours of the following two complex ions: $[\text{Cu(H}_2\text{O})_6]^{2+}$ and $[\text{CuCl}_4]^{2-}$.
State the shape adopted by the $[\text{CuCl}_4]^{2-}$ ion.
Write down the expression for the stability constant, $K_{\text{stab}}$, for this equilibrium.
Copper also forms the complex ions $[\text{Cu(NH}_3)_2(\text{H}_2\text{O})_4]^{2+}$ and $[\text{Cu(en)(H}_2\text{O})_4]^{2+}$ where en is the bidentate ligand ethane-1,2-diamine, $\text{H}_2\text{NCH}_2\text{CH}_2\text{NH}_2$. What is meant by the expression bidentate ligand?
The table gives the stability constants for these two complexes. What do the $K_{\text{stab}}$ values show about the relative positions of equilibria 1 and 2?
Nickel forms the complex ion $[\text{Ni(en)}_3]^{2+}$ in which it is surrounded octahedrally by six nitrogen atoms. Name the kind of stereoisomerism shown by $[\text{Ni(en)}_3]^{2+}$.
Draw 3D diagrams to represent the two stereoisomers of $[\text{Ni(en)}_3]^{2+}$.
Ethane-1,2-diamine is a useful reagent in organic chemistry. Explain how the amino groups in ethane-1,2-diamine enable the molecule to act as a Brønsted-Lowry base.
Write an equation for the reaction between ethane-1,2-diamine and excess hydrochloric acid.
Under certain conditions, ethane-1,2-diamine reacts with ethanedioic acid, $\text{HO}_2\text{CCO}_2\text{H}$, to produce polymer $Z$. Draw the structure of polymer $Z$, showing two repeat units.
Name the type of reaction that occurs during this polymerisation.
Polymer $Z$ is an example of a biodegradable polymer. Name a polymer that is non-biodegradable.