Complete Table 1.1 to show how many electrons are in the $3p$ subshell and how many unpaired electrons are present in an atom of P, S and Cl.
Construct an equation that represents the first ionisation energy of P.
Three candidate values for the first ionisation energy of S are listed: $1000\ \text{kJ mol}^{-1}$, $1160\ \text{kJ mol}^{-1}$, $1320\ \text{kJ mol}^{-1}$. Circle the correct one. Justify your selection by comparing it with the values of P and Cl.
For $\text{P}^{3-}$, $\text{S}^{2-}$ and $\text{Cl}^-$, the electron counts are the same. Give the complete electronic configuration of $\text{P}^{3-}$.
State the ionic radius trend shown by $\text{P}^{3-}$, $\text{S}^{2-}$ and $\text{Cl}^-$. Explain your answer.
A student carries out three tests on separate samples of $\text{NaCl}(aq)$. Complete Table 1.2 with the observations made in each test: (1) addition of a few drops of $\text{Br}_2(aq)$, (2) addition of a few drops of concentrated $\text{H}_2\text{SO}_4$, (3) addition of a few drops of dilute $\text{AgNO}_3(aq)$.
$\text{POCl}_3$ shows chemical properties similar to $\text{PCl}_5$. $\text{POCl}_3$ has a melting point of $1^{\circ}\text{C}$ and a boiling point of $106^{\circ}\text{C}$. $\text{POCl}_3$ reacts vigorously with water, producing misty fumes and an acidic solution. Explain how the information in (d) suggests that the structure and bonding of $\text{POCl}_3$ are simple covalent.
Construct an equation for the reaction of $\text{POCl}_3$ with water. $\text{POCl}_3 + \dots \rightarrow \dots$
$\text{POCl}_3$ contains a double covalent bond between P and O. Complete the dot-and-cross diagram in Fig. 1.1 to show the bonding in $\text{POCl}_3$. Show outer shell electrons only.
POCl$_3\text{(g)}$ is produced when PCl$_3\text{(g)}$ reacts with O$_2\text{(g)}$. $2\text{PCl}_3\text{(g)} + \text{O}_2\text{(g)} \rightarrow 2\text{POCl}_3\text{(g)}$
Define enthalpy change of formation, $\Delta H_f$.
Calculate the bond energy of P$=$O in POCl$_3$ using the data in Table 1.3. Show your working.