Na reacts with $\text{O}_2$ to make $\text{Na}_2\text{O}$. In this reaction, Na acts as the reducing agent. Define reducing agent.
Write an equation showing the reaction between $\text{Na}_2\text{O}$ and water.
$\text{Al}_2\text{O}_3$ is an amphoteric oxide in bauxite. State what amphoteric means.
$\text{Al}_2\text{O}_3$ is extracted from bauxite through several stages. In the first stage, $\text{Al}_2\text{O}_3$ is heated with an excess of $\text{NaOH(aq)}$, producing a colourless solution. Write an equation for this reaction.
The dehydration of alcohols uses $\text{Al}_2\text{O}_3$ as a catalyst. State the effect of using $\text{Al}_2\text{O}_3$ as a catalyst in the dehydration of alcohols. Use the Boltzmann distribution in Fig. 2.1 to help explain your answer.
Solid $\text{P}_4\text{O}_6$ is a white solid with melting point $24\,^{\circ}\text{C}$. When solid $\text{P}_4\text{O}_6$ reacts with water, $\text{H}_3\text{PO}_3$ is formed. Deduce the structure and bonding in $\text{P}_4\text{O}_6$. Explain your answer.
Determine the oxidation number of $\text{P}$ in $\text{H}_3\text{PO}_3$.
Heating $\text{P}_4\text{O}_6(\text{s})$ with oxygen gives $\text{P}_4\text{O}_{10}(\text{s})$. $\text{P}_4\text{O}_6(\text{s}) + 2\text{O}_2(\text{g}) \rightarrow \text{P}_4\text{O}_{10}(\text{s})$, $\Delta H = -1372\,\text{kJ mol}^{-1}$. The enthalpy change of formation, $\Delta H_f$, of $\text{P}_4\text{O}_{10}(\text{s})$ is $-3012\,\text{kJ mol}^{-1}$. Calculate the enthalpy change of formation, $\Delta H_f$, of $\text{P}_4\text{O}_6(\text{s})$.
Write an equation showing the reaction of $\text{P}_4\text{O}_{10}$ with water.
Atmospheric $\text{SO}_2$ and $\text{SO}_3$ are present in the atmosphere. The atmospheric oxidation of $\text{SO}_2$ to $\text{SO}_3$ is catalysed by $\text{NO}_2$. The first stage of the catalytic oxidation is shown in equation 1: $\text{SO}_2(\text{g}) + \text{NO}_2(\text{g}) \rightleftharpoons \text{SO}_3(\text{g}) + \text{NO}(\text{g})$. Construct an equation to show how $\text{NO}_2$ is regenerated in the catalytic oxidation of $\text{SO}_2$.
When $\text{NO}_2$ reacts with unburned hydrocarbons, it can produce photochemical smog. State the product of this reaction that contributes to photochemical smog.
Fig. 2.2 shows how atmospheric temperature changes with height above the ground. The equilibrium reaction in equation 1 has $\Delta H_r = -168\,\text{kJ mol}^{-1}$. Suggest how the position of this equilibrium differs at a height of $20\,\text{km}$ compared with a height of $50\,\text{km}$ from the ground. Explain your answer.
Suggest how this equilibrium position changes at $20\ \text{km}$ in comparison with $50\ \text{km}$ above the ground. Explain your answer.