The complete combustion equation for P, $\text{C}_4\text{N}_2(l)$, is given here: $\text{C}_4\text{N}_2(l) + 4\text{O}_2(g) \rightarrow 4\text{CO}_2(g) + \text{N}_2(g)$, $\Delta H = -2036\,\text{kJ mol}^{-1}$. The enthalpy change of formation, $\Delta H_f$, of $\text{CO}_2(g)$ is $-384\,\text{kJ mol}^{-1}$. Calculate the enthalpy change of formation, $\Delta H_f$, of P, in $\text{kJ mol}^{-1}$.
One product of the complete combustion of P is nitrogen gas, $\text{N}_2(g)$. Explain why nitrogen is unreactive.
Q is produced when HCN reacts with ethyne, $\text{H}\! - \! \text{C} \! \equiv \! \text{C} \! - \! \text{H}$. Ethyne, HCN and Q are all weak Brønsted-Lowry acids. Explain what is meant by the term weak Brønsted-Lowry acid.
Ethyne, HCN and Q each contain triple bonds between two atoms. A triple bond is made up of one sigma ($\sigma$) bond and two pi ($\pi$) bonds. Draw a labelled diagram to show how one pi ($\pi$) bond is formed.
P and Q may be identified in the atmosphere by infrared spectroscopy. Identify two absorptions, and the bonds corresponding to these absorptions, that would be seen in the infrared spectra of both P and Q.
The flow chart shows some reactions of R. Name the type of reaction shown in reaction 1.
Draw the structure of S, the organic product of reaction 2.
Name T.
T can also be made by reacting $\text{CH}_3\text{CH}_2\text{CH}_2\text{Br}$ with ammonia. State the conditions needed for this reaction.