Complete Table 1.1 by giving the number of electrons in the $3p$ subshell and the total number of unpaired electrons for atoms 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 supplied: $1000\ \text{kJ mol}^{-1}$, $1160\ \text{kJ mol}^{-1}$, $1320\ \text{kJ mol}^{-1}$. Circle the correct one. Explain your selection by comparing it with the values for P and Cl.
Give the full electronic configuration of $\text{P}^{3-}$.
State the trend in ionic radius for $\text{P}^{3-}$, $\text{S}^{2-}$ 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) adding a few drops of $\text{Br}_2\text{(aq)}$, (2) adding a few drops of concentrated $\text{H}_2\text{SO}_4$, (3) adding a few drops of dilute $\text{AgNO}_3\text{(aq)}$.
$\text{POCl}_3$ has similar chemical properties to $\text{PCl}_5$. $\text{POCl}_3$ melts at $1^{\circ}\text{C}$ and boils at $106^{\circ}\text{C}$. $\text{POCl}_3$ reacts vigorously with water, giving misty fumes and an acidic solution. Explain how the information in (d) suggests that the structure and bonding of $\text{POCl}_3$ is simple covalent.
Construct an equation for the reaction between $\text{POCl}_3$ and water. $\text{POCl}_3 + \ldots \rightarrow \ldots$
$\text{POCl}_3$ has 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 only outer-shell electrons.
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.