November's AP Problem

a)      How many moles of Ba(IO₃)₂ are contained in 1.0 liter

        of a saturated solution of this salt at 25° C.  

        K_sp of Ba(IO₃)₂ is 6.5 x 10^-10

b)      When 0.100 liter of 0.060 molar Ba(NO₃)₂ and 0.150 liter

        of 0.12 molar KIO₃ are mixed at 25° C, how many milligrams

        of barium ion remain in each milliliter of the solution?

        Assume that the volumes are additive and that all activity

        coefficients are unity.