What is the molar solubility of PbBr2?? the Ksp=6.6e-6?

Question

What is the molar solubility of PbBr2?? the Ksp=6.6e-6?

Answer 1

What I did was set up a reaction table.

.................. PbBr2(s)..... <-->...... Pb2+(aq)....+..... 2Br-(aq)

Initial............... -................................ 0......................... 0

Reacting......... -.............................. +x....................... +2x

Equilibrium..... -................................ x......................... 2x

[Pb2+] = x [Br-] = 2x

Write out the solubility product constant.

Ksp = [Pb2+][Br-]^2       Ksp = 6.6*10^-6

6.6*10^-6 = (x)(2x)^2

6.6*10^-6 = x(4x^2)

6.6*10^-6 = 4x^3

There is a one to one mole ratio between Pb2+ and PbBr2.

x = [Pb2+] = [PbBr2] = .0118M