(a)[2]
Define electron affinity.
(b)[1]
Write the equation for calcium’s second ionisation energy process. Include state symbols.
(c)[3]
Oxygen is present as $\text{O}_2$ molecules. Use the information provided here to calculate the bond energy of the $\text{O} = \text{O}$ bond. Show your working clearly.
(d(i))[1]
Suggest why oxygen’s first electron affinity is negative.
(d(ii))[1]
Suggest why oxygen’s second electron affinity is positive.
(e)[2]
Calculate the enthalpy of formation for calcium oxide, $\text{CaO(s)}$.
(f)[2]
The lattice energy of lithium fluoride, $\text{LiF(s)}$, is $-1022\,\text{kJ mol}^{-1}$.\n\nIdentify the factor that makes the lattice energy of calcium oxide more exothermic than that of lithium fluoride. Explain why this factor leads to the difference in lattice energies.