The compound Co(NH3)4BrSO₄ exhibits ionization isomerism. This occurs when the counter ion in a complex salt is itself a potential ligand and can displace a ligand that is

d)

i)
The compound $\text{Co}(\text{NH}_3)_4\text{BrSO}_4$ exhibits ionization isomerism. This occurs when the counter ion in a complex salt is itself a potential ligand and can displace a ligand that is already in the coordination sphere.

ii)
The structural formulae of the isomers are:

1. $[\text{Co}(\text{NH}_3)_4\text{Br}]\text{SO}_4$ (Bromide is a ligand, sulfate is the counterion)
2. $[\text{Co}(\text{NH}_3)_4\text{SO}_4]\text{Br}$ (Sulfate is a ligand, bromide is the counterion)

e)
The complex $[\text{Cu}(\text{H}_2\text{NCH}_2\text{CH}_2\text{NH}_2)_2]^{2+}$ has a coordination number of 4 (each ethylenediamine ligand, $\text{H}_2\text{NCH}_2\text{CH}_2\text{NH}_2$, is bidentate). Copper(II) complexes with a coordination number of 4 typically adopt a square planar geometry.

5 (a)

i)

Steps	Reagent and conditions
i	$\text{Br}_2$, UV light / heat
ii	$\text{KCN}$ (or $\text{NaCN}$), ethanolic solution, heat (reflux)
iii	Dilute $\text{H}_2\text{SO}_4$ (or $\text{HCl}$ or $\text{NaOH}$), heat (reflux)
iv	Alcoholic $\text{KOH}$ (or $\text{NaOH}$), heat (reflux)
v	$\text{HBr}$, room temperature

ii)
The structures of compounds D, E, and F are:
D: $\text{CH}_3\text{CH}_2\text{CH}_2\text{COOH}$ (Butanoic acid)
E: $\text{CH}_3\text{CH}=\text{CH}_2$ (Propene)
F: $\text{CH}_3\text{CH}(\text{Br})\text{CH}_3$ (2-Bromopropane)