The species $[\text{MnCl}_4]^{2-}$ is a complex ion. Deduce the oxidation state of manganese in $[\text{MnCl}_4]^{2-}$.
The $[\text{MnCl}_4]^{2-}$ complex does not include any $180^\circ$ bond angles. Produce a three-dimensional diagram to show the shape of the $[\text{MnCl}_4]^{2-}$ complex. State one bond angle on your diagram.
A solution containing $[\text{Co(H}_2\text{O)}_6]^{2+}$ is treated with excess $\text{NaOH(aq)}$. Write an equation for this reaction. State one observation that can be made immediately after the reaction, including the colour and state of the cobalt-containing product.
A solution containing $[\text{Co(H}_2\text{O)}_6]^{2+}$ is treated with excess $\text{NH}_3\text{(aq)}$. Write an equation for this reaction. State one observation that can be made immediately after the reaction, including the colour and state of the cobalt-containing product.
A solution containing $[\text{Co(H}_2\text{O)}_6]^{2+}$ is treated with excess $\text{NaCl(aq)}$. Write an equation for this reaction. State one observation that can be made immediately after the reaction, including the colour and state of the cobalt-containing product.
Name the type of reaction that takes place in (b)(iii).
The complex ion $[\text{Co(NH}_3\text{)}_2(\text{en})_2]^{2+}$ is formed by cobalt. The abbreviation $\text{en}$ is used for the bidentate ligand 1,2-diaminoethane, $\text{H}_2\text{NCH}_2\text{CH}_2\text{NH}_2$. Define the term bidentate ligand.
Draw three-dimensional diagrams of the two optical isomers of $[\text{Co(NH}_3\text{)}_2(\text{en})_2]^{2+}$. Each en ligand may be shown as N- -N.
Cobalt forms the complex ion $[\text{Co(NH}_3)_2(\text{en})_2]^{2+}$. The abbreviation en is used for the bidentate ligand 1,2-diaminoethane, $\text{H}_2\text{NCH}_2\text{CH}_2\text{NH}_2$. This complex ion exhibits both geometrical and optical isomerism.