Consider a saturated aqueous solution of barium oxalate Ba(C2O4) while the solution is buffered at pH 3.0. The solubility product, Ksp for Ba(C2O4) is 1.0 x 10-6, the acid dissociation constants, Ka1 and Ka2, for oxalic acid, H2C2O4 are 5.6 x 10-2 and 5.4 x 10-5, respectively as well as the autoprotolysis constant for H2O, Kw is 1.0 x 10-14.