Write an equation for the reaction between sodium and oxygen to make sodium oxide. Include state symbols.
Explain why the melting point of sodium oxide is high.
Explain why the solution formed is alkaline. Your answer should make use of the Brønsted-Lowry theory of acids and bases.
Calculate the pH of the solution formed when $3.10\,\text{g}$ of sodium oxide are added to $400\,\text{cm}^3$ of water.
Use the data below, together with any other appropriate data from the Data Booklet, to find the lattice energy of sodium oxide, $\Delta H_{\text{latt}}^\circ\,\text{Na}_2\text{O(s)}$.
State how $\Delta H_{\text{latt}}^\circ\,\text{Na}_2\text{S(s)}$ compares with $\Delta H_{\text{latt}}^\circ\,\text{Na}_2\text{O(s)}$. Show this by placing a tick ($\checkmark$) in the correct box in the table. Explain your answer.