What observation would you make in reaction 1?
Name the type of reaction occurring in reaction 2.
$\text{H}_3\text{PO}_4$ may be formed by the direct reaction of phosphorus with nitric acid. $\text{P} + 5\text{HNO}_3 \rightarrow \text{H}_2\text{O} + 5\text{NO}_2 + \text{H}_3\text{PO}_4$ Use oxidation numbers to prove that this reaction is a redox reaction.
Reaction 3 is a neutralisation reaction in which $\text{NH}_3$ acts as a base. Explain how $\text{NH}_3$ behaves as a base in reaction 3.
Draw the three-dimensional shape of the ammonium ion, $\text{NH}_4^+$. State the bond angle.
State one industrial use of compounds such as $(\text{NH}_4^+)(\text{H}_2\text{PO}_4^-)$.
$\text{PCl}_5$ can be used to change alcohols into halogenoalkanes. Write an equation for the reaction of $\text{C}_2\text{H}_5\text{OH$ with $\text{PCl}_5$ to make $\text{C}_2\text{H}_5\text{Cl}$.
State the type of reaction in (i).
Halogenoalkanes can also be made by reacting alcohols with hydrogen halides, such as $\text{HCl}$ and $\text{HI}$. • $\text{HCl}$ is made using $\text{NaCl}$ and concentrated $\text{H}_2\text{SO}_4$. • $\text{HI}$ is made by reacting $\text{NaI}$ with concentrated $\text{H}_3\text{PO}_4$. Suggest why $\text{HI}$ is not made by reacting $\text{NaI}$ with concentrated $\text{H}_2\text{SO}_4$.
The rate of hydrolysis of halogenoalkanes with $\text{NaOH}(aq)$ depends on which halogen is attached to the carbon. State and explain the order of reactivity when $\text{NaOH}(aq)$ reacts separately with $\text{C}_2\text{H}_5\text{Cl}$, $\text{C}_2\text{H}_5\text{Br}$ and $\text{C}_2\text{H}_5\text{I}$.