Question

The concentration of pb2+ in a solution saturated with pbbr2(s) is 2.14 ✕ 10-2 m. calculate ksp for pbbr2.

Answer 1

Concentration = 2.14 âś• 10-2 m 
For [Br-], there are 2 ions so 2 x 2.14 x 10^-2 =4.28 x 10^-2  
Ksp = [Pb][Br]^2 = 2.14 âś• 10-2 x (4.28 x 10^-2 )^2 = 39.20 x 10^-6 
Ksp = 3.92 x 10^-5