Question
Only 0.0640 grams of PbF2 will dissolve in 100.0 mL of solution. From this data, calculate the Ksp by two methods.
Answers
DrBob222
Which method do you know?
sea lively
Ksp=produts molarity/reatants molarity
DrBob222
Then you dont know either.
mols PbF2 dissolved - 0.064/molar mass PbF2 = Estimated 0.0004
............PbF2(s) ==> Pb^2+ + 2F^-
I..........solid.................0............0
C.........solid............0.0004.....0.0008
E.........solid............0.0004......0.0008
Ksp = (Pb^2+)(F^-)^2
Ksp = (0.0004)(0.0008)^2 = ?
Another method.
............PbF2 ==> Pb^2+ + 2F^-
I..........solid...........0..............0
C.........solid...........x..............2x
E.........solid...........x..............2x
Ksp = (Pb^2+)(F^-)^2
Ksp = (x)(2x)^2 = 4x^3
You know x = estimated 0.0004 so
Ksp = 4*0.0004)^3 approximately.
Don't forget to get more accurate numbers
mols PbF2 dissolved - 0.064/molar mass PbF2 = Estimated 0.0004
............PbF2(s) ==> Pb^2+ + 2F^-
I..........solid.................0............0
C.........solid............0.0004.....0.0008
E.........solid............0.0004......0.0008
Ksp = (Pb^2+)(F^-)^2
Ksp = (0.0004)(0.0008)^2 = ?
Another method.
............PbF2 ==> Pb^2+ + 2F^-
I..........solid...........0..............0
C.........solid...........x..............2x
E.........solid...........x..............2x
Ksp = (Pb^2+)(F^-)^2
Ksp = (x)(2x)^2 = 4x^3
You know x = estimated 0.0004 so
Ksp = 4*0.0004)^3 approximately.
Don't forget to get more accurate numbers