Homework SourseCalculate the molar solubility of leadII fluoride PbF2 Ksp
Calculate the molar solubility of lead(II) fluoride, PbF2. Ksp = 3.7 x 10-8._____M The concentration of Pb2+ ion in a saturated solution of PbF2 is_____M The concentration of F- ion in a saturated solution of PbF2 is_____M
Solution
PbF2 : Ksp = 3,7•10^-8
- - - - - - - - - - - - - - - - -
. . PbF2 . . . -------> . . . Pb(2+) . . . + . . . 2 F(-)
. .1 mole . . . . . . . . . . . . .1 mole . . . . . . . . 2 moles
. . . according the equation :
[Fe(2+)] = s
[HO(-)] = 2 s
Ksp = [Pb(2+)] x [F(-)] ²
Ksp = s x (2s) ²
Ksp = 4 s ³
. . . therefore :
s = ³âˆš(Ksp / 4)
s = ³âˆš(3,7•10^-8 / 4)
s = 2,10•10^-3 mole/Liter
. . . then :
[Pb(2+)] = s = 2,10•10^-3 mole/Liter
. . . and
[F(-)] = 2s = 4,20•10^-3 mole/Liter
