Q < Ksp Unsaturated solution Q = Ksp Saturate solution Q > Ksp Oversaturate solution Predicting Precipitation VIDEO You Tube VIDEO My Channel Unit 12 Subjects . The rate of a chemical reaction between substances A and B is found to follow the rate equation Barium sulphate, BaSO 4 Unit 1 : AP Stoichiometry 1 : Empirical formula and percent composition A saturated solution of BaSO4 is given to patients needing digestive tract x-rays. X 70 X 70 Èc CO in a. solutio . — 50 x/0 Sp - ? a) FeS b) Bi 2 S c) Ag 2 CO 3 d) Al(OH) 3 e) PbI 2 f) Cu(OH) 2 g) PbCrO 4 h) Sb 2 S 3 2. They therefore need different concentrations of one needed) and compare with Ksp: o Q>Ksp, precipitate will form o Q=Ksp, at equilibrium o Q