We have a solution that contains 0.010 M Ce3+ and 0.10 M Ca2+. Would it be possible to precipitate out 99.9% of the Ce3+ without co-precipitate Ca2+? There are sodium hydroxide (NaOH) and sodium oxalate (Na2C204) available in the lab. Which of the chemicals would meet the requirement? To answer this question, you have to do all the calculations needed. Ksp of CaC204 = 1.3 x10-8; Ksp of Cez (C204)3 = 5.9 x 10-30 Ksp of Ce(OH)3 = 6.0 x 10-22; Ksp of Ca(OH)2 = 6.5 x 10-6