how many moles of PbCl2 will dissolve in 1.0 L of 0.051 M NaCl solution. how do i do this?

Just as Ricki said, you need to use the ksp value for PbCl2 to figure how many moles of PbCl2 will dissolve in the solution. According to my book, the ksp value of PbCl2 is 1.6 x 10-5. You then solve this problem like any other equilibrium problem. PbCl2(s)> 2Cl- (aq) + Pb 2+(aq). The equilibrium equation would be the concentrations of products over the reactants in molarity. However, solids are never in the equilibrium equation since solids remain constant. The insertion of the solid PbCl2 into a sodium chloride solution decreases the solublity of PbCl2 due to the common ion effect. The overall equilibrium equation is (.051+2x)^2 (X)= 1.6 x 10-5. x= .004457 which equals the molar solubility of PbCl2. Hence, the amount of moles of PbCl2 that will dissolve in the solution.