2NaF + CaCl2 �¨ CaF2 + 2NaCl

Question

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?

Answer 1

Ya gotta have more info, like the mass of the CaF2 pptd.

Answer 2

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.

Answer 3

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

Answer 4

Thanks!