Given:
- Ksp of CaSO4 is 7.10*10^-5
- Molar mass of Na2SO4 is 142.04g/mol
My Attempt:
Step 1 - figure out molar solubility of CaSO4
√7.10*10^-5 = 8.43*10^-3M
Step 2 - convert Na2SO4 from mass to moles
105mg = 0.105g 0.105/142.04 = 7.39*10^-4 mol
Step 3 - figure out moles of CaSO4 produced
Since we need 1 mol of Ca2+ & 1 mol of Na2SO4 to form 1 mol of CaSO4 And we have less Na2SO4 than Ca2+
CaSO4 produced = 7.39*10^-4 mol
Step 4 - figure out molarity of CaSO4
7.39*10^-4mol / 100ml = 7.39*10^-3 / L = 7.39*10^-3M
Step 5 - figure out if any CaSO4 precipitates
8.43*10^-3M > 7.39*10^-3M Therefore NO CaSO4 precipitates
The answer in the book is a Yes, can anyone please explain to me where I have gone wrong? Thanks!