In the mass spectrum of $\text{PCl}_3$, a number of peaks appear because several molecular fragments are present. Propose the isotopic make-up of the fragments with mass numbers 101, 103 and 105.
State the relative ratios of the heights of the three peaks for these fragments.
Draw a ‘dot-and-cross’ diagram to represent the bonding in $\text{PCl}_5$. Show only the outer electrons.
Draw diagrams to show the shapes of $[\text{PCl}_4]^+$ and $[\text{PCl}_6]^-$.
Phosphorus(III) oxide, $\text{P}_4\text{O}_6$, has no P-P or O-O bonds. In the $\text{P}_4\text{O}_6$ molecule, all oxygen atoms are divalent and all phosphorus atoms are trivalent. Sketch a structure for $\text{P}_4\text{O}_6$.
$\text{P}_4\text{O}_6$ can act as a ligand. What does the term ligand mean?
Write an expression for the solubility product, $K_{sp}$, of $\text{Ca}_3(\text{PO}_4)_2$.
At $298\ \text{K}$, the solubility of $\text{Ca}_3(\text{PO}_4)_2$ is $2.50 \times 10^{-6}\ \text{mol dm}^{-3}$. Calculate the solubility product, $K_{sp}$, of $\text{Ca}_3(\text{PO}_4)_2$ at this temperature. Include the units.
What is meant by the term lattice energy?
Explain why the lattice energy of calcium phosphate is less exothermic than that of magnesium phosphate.