A saturated solution of #PbBr_2# is prepared by dissolving the solid salt in water. The concentration of #Pb_2^+# in solution is found to be 0.0115 M. What is the Ksp for #PbBr_2#?

1 Answer
Jul 14, 2017

Answer:

#K_(sp)=6.1xx10^-6#

Explanation:

We interrogate the solubility equilibrium.........

#PbBr_2(s) rightleftharpoonsPb^(2+) + 2Br^(-)#

Now #K_(sp)=[Pb^(2+)][Br^-]#.........And if we say that the solubility of #PbBr_2-=S#, then by stoichiometry........

#K_(sp)=[S][2S]^2=4S^3# (because #S=[Pb^(2+)]#, and #[Br^-]=2S#

#=4xx(0.0115)^3=6.1xx10^-6#.........

Can you define what is meant by a #"saturated solution......?"#