Complete the table by placing one tick (✓) in each row to show the sign of each type of energy change under standard conditions.
Explain what the term enthalpy change of atomisation means.
The overall equation for atomising liquid bromine molecules, $\text{Br}_2(l)$, is given below. $\text{Br}_2(l) \rightarrow 2\text{Br}(g)$ This occurs in two stages. • Draw a labelled energy cycle to show this atomisation process, including the state symbols. • Use your cycle and the data from the Data Booklet to calculate the enthalpy change of vaporisation of $\text{Br}_2(l)$, $\Delta H_{vap}^\ominus$. For bromine, the enthalpy change of atomisation, $\Delta H_{at}^\ominus = +112\,\text{kJ mol}^{-1}$.
Suggest how the $\Delta H_{vap}^\ominus$ of iodine, $\text{I}_2(l)$, would differ from that of bromine, $\text{Br}_2(l)$. Explain your answer.
Explain what the term enthalpy change of hydration means.
Suggest why the enthalpy change of hydration of $\text{Br}^-(g)$ is more exothermic than the enthalpy change of hydration of $\text{I}^-(g)$.