posted by Neha .
2NaF + CaCl2 ¨ CaF2 + 2NaCl
An excess of 0.20 M NaF is used to precipitate the calcium ions from a
50.0 mL sample of a calcium chloride solution. What is the concentration
of the original calcium chloride solution?
Ya gotta have more info, like the mass of the CaF2 pptd.
In regards to DrBob222, there were 3 parts to this question; the first part said there were .1952 g and the mols were 2.504 * 10^-3 mol. But I don't know if this part refers to the first part because it doesn't sound like it does.
0.1952 g CaCl2/molar mass CaF2 = 0.002504 mole CaF2. Convert that to moles CaCl2 which is 0.002504.
Then concn CaCl2 = mole CaCl2/L soln = ? 0.002504/0.050 L = ??M