Lanthanum(III) sulfate is an inorganic compound with the formula La2(SO4)3·xH2O (0 ≥ x ≥ 9).
It forms various hydrates, the most common one being the nonahydrate, which are all white solids.
It is an intermediate in producing lanthanum from its ores.
[4] The nonahydrate is produced by dissolving lanthanum or lanthanum hydroxide in dilute sulfuric acid, then evaporating the solution:[5] The anhydrous compound can be produced by heating the hydrates to 300 °C.
If heated further, anhydrous lanthanum(III) sulfate decomposes to La2O2SO4 at 775 °C, which in turn decomposes to lanthanum(III) oxide at 1100 °C.