Chemical Properties
white, rhomb crystal(s) when pure, else colored yellow, orange, pink; radioactive [HAW93] [CRC10]
Description
Radium sulfate has the molecular formula of RaSO4
and the molecular weight of 322.0626 g/mol. It can be
prepared by dissolving radium oxide in sodium sulfate
solution:
RaO+Na2SO4+H2O ? RaSO4+NaOH
Radium sulfate is insoluble in water with a solubility
product of 3.66×10-11. The solubility of radium sulfate
would appear as at least 100-fold less than barium
sulfate. Thus, it is the most insoluble sulfate known. Its
CAS Number is 7446-16-4. It appears as white crystals.
Since radium is a decay product in the 238U series which
then allows radon to accumulate in household basements,
it is RaSO4 that has received some attention in
the scientific literature.
Uses
Radium sulfate (RaSO4) is the most insoluble sulfate known in chemistry and is created
when radium combines with a sulfate ion (Ra + H2SO4 → RaSO4 + H2↑).