Caesium hydrogen sulfate

Caesium hydrogen sulfate is an ionic compound with formula CsHSO4.
CsHSO4 is synthesized via a 1:1 molar reaction between Cs2SO4 and H2SO4. Both compounds are dissolved in DI water, and placed in a 60 °C oven with warm air flowing over the top of the mixing beaker. Once the solution is at half of its initial volume it is cooled to 5 °C. At this point there will be four molecules in the solution: Cs2SO4, H2SO4, CsHSO4, and H2O. At 5 °C only CsHSO4 will precipitate into a crystalline solid. This makes for easy separation by filtration. The remaining wet CsHSO4 can be dried in a vacuum dedicator.