Write an equation for sodium's reaction with oxygen to form sodium oxide. Include state symbols.
Explain why the melting point of sodium oxide is high.
When sodium oxide reacts with water, an alkaline solution forms. Explain why this solution is alkaline. In your answer, use the Brønsted-Lowry theory of acids and bases.
Calculate the pH of the solution formed when $3.10\,\text{g}$ of sodium oxide is added to $400\,\text{cm}^3$ of water.
Using the data below, together with any other suitable values from the Data Booklet, calculate the lattice energy of sodium oxide, $\Delta H^{\circ}_{\text{latt}}\ \text{Na}_2\text{O(s)}$.
State the way in which $\Delta H^{\circ}_{\text{latt}}\ \text{Na}_2\text{S(s)}$ differs from $\Delta H^{\circ}_{\text{latt}}\ \text{Na}_2\text{O(s)}$. Show this by putting a tick ($\checkmark$) in the correct box in the table. Explain your answer.