CaMoO4 and CaWO4 solubility in diluted CaCl2 solutions and seawater wa
s studed. Thermodynamic and apparent solubility products are equal 3.0
9 x 10(-8) and 9.22 x 10(-7) for CaMoO4 at 22 degrees C, 1.24 x 10(-9)
and 9.40 x x 10(-8) for CaWO4 at 19 degrees C, respectively. Total ac
tivity coefficient and free ion fraction in seawater are equal to 0.16
4 and 0.724 for MoO42- and 0.065 and 0.287 for WO42-, respectively.