question: Determine the Ksp of salt AB2 if the molar solubility is
0.00015 mol/L
1.Write the llbm dissociation rxn.
2. Write the Ksp expression.
3. Set up the ICE chart.
4. Use molar solubility to determine [ion]llbm
5.Sub into Ksp expression.
AB2 (s) <=> A+(aq) + 2B-(aq) Ksp=[A+][B-]2
I n/a 0 0
C n/a
E n/a 0.00015* 2(0.00015)
* for every mole of A+ that is present at llbm, one mole of AB2 dissolved
Ksp = (0.00015)(0.00030)2
Ksp = 1.4x10-11 for AB2
Sometimes the molar solubility info can be 'hidden':
for example, a saturated solution contains 0.24g of salt per 500mL.
[Use molar mass, convert the given info to mol/L]
Homework:
p486(4)
p493(7,8,9,12)
...not all are molar solblty to Ksp, some are Ksp to molar solblty
What would you get if image 1 and image 2 were combined.
[Ans: a molar solution.]
