The table shows the first three ionisation energies of aluminium - Scottish Highers Chemistry - Question 4 - 2018

To find the enthalpy change for the reaction where aluminium gas loses two electrons to form Al²⁺, we need to consider the ionization energies provided:

1. First Ionization Energy: This is the energy required to remove the first electron: 578 kJ mol⁻¹.
2. Second Ionization Energy: This is the energy required to remove the second electron: 1817 kJ mol⁻¹.

The total enthalpy change for the reaction can be calculated by summing the first and second ionization energies:

$ext{Total Enthalpy Change} = ext{First IE} + ext{Second IE} = 578 ext{ kJ mol}^{-1} + 1817 ext{ kJ mol}^{-1} = 2395 ext{ kJ mol}^{-1}$

Thus, the enthalpy change for the reaction is 2395 kJ mol⁻¹, corresponding to option B.