Example:Supposing 10.0L of 0.010mol-L-BaCl2 is added to 40.0L of a solution that contains SO2-ion with a concentration of 6.0X 10-4 mol-L-at 25C. Does BaSO precipitate?If so,how many grams of BaSO,are formed?What is the concentration of SO2- in the final solution? K9=1.1x100 Answer: c(S0)= 6.0×104×40.0 =4.8×104molL 50.0 c(Ba2+)= 0.010×10. 2=2.0x103molL 50.0 Example：Supposing 10.0L of 0.010mol·L-1 BaCl2 is added to 40.0L of a solution that contains SO4 2- ion with a concentration of 6. 0×10-4 mol·L-1 at 25℃. Does BaSO4 precipitate? If so, how many grams of BaSO4 are formed? What is the concentration of SO4 2- in the final solution? Answer: 4 1 4 2 o 4 4.8 1 0 mol L 5 0.0 6.0 1 0 4 0.0 (SO ) - - - - =     c = 2 3 1 o 2.0 10 mol L 50.0 0.010 10.0 (Ba ) + - - =    c = 10 sp 1.1 10- K = 