The mass spectrum of $\text{PCl}_3$ shows a number of peaks that correspond to different molecular fragments. Suggest the isotopic composition of the fragments with mass numbers 101, 103 and 105.
State the relative ratios of the peak heights for the three peaks that correspond to these fragments.
Draw a ‘dot-and-cross’ diagram to illustrate the bonding in $\text{PCl}_5$. Include only the outer electrons.
Draw diagrams to indicate 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. Within the $\text{P}_4\text{O}_6$ molecule, every oxygen atom is divalent and every phosphorus atom is trivalent. Sketch a structure for $\text{P}_4\text{O}_6$.
$\text{P}_4\text{O}_6$ can act as a ligand. What is meant by the term ligand?
Write an expression for the solubility product, $K_{sp}$, of $\text{Ca}_3(\text{PO}_4)_2$.
The solubility of $\text{Ca}_3(\text{PO}_4)_2$ is $2.50 \times 10^{-6}\,\text{mol dm}^{-3}$ at $298\,\text{K}$. Calculate the solubility product, $K_{sp}$, for $\text{Ca}_3(\text{PO}_4)_2$ 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.