Rubidium Tetramolybdates

Including the octamolybdates, which are regarded as acid tetramolybdates, a number are known, corresponding to the formulae Rb₂O.4MoO₃, Rb₂O.4MoO₃.O.5H₂O, Rb₂O.4MoO₃.4H₂O, and Rb₂O.H₂O.8MoO₃.3H₂O; the salt Rb₂O,MoO₃.Rb₂O.3MoO₃.5H₂O is regarded as a double salt.

Other rubidium molybdates are: 4Rb₂O.5MoO₃.12H₂O; 5Rb₂O.7MoO₃.6.5H₂O; 3Rb₂O.8MoO₃.6H₂O; Rb₂O.11MoO₃.5.5H₂O; Rb₂O.13MoO₃.4H₂O; Rb₂O.18MoO₃.