posted by jade .
CrCl3(s) + AgNO3 (aq)= AgCl(s) + Cr(NO3)3(aq)
A 0.750 g sample of impure CrCl3 was removed from a bottle that contained 1.75 g of impure sample. The removed sample was dissolved in water and required 42.5 mL of 0.215 M AgNO3 solution to react with the CrCl3 in the sample. What was the mass percent of CrCl3 in the sample?
CrCl3 + 3AgNO3 ==> 3AgCl + Cr(NO3)3
moles AgNO3 used = M x L = ?.
moles CrCl3 = 1/3 x moles AgNO3.
g CrCl3 = mols x molar mass
%CrCl3 = (grams CrCl3/mass sample)*100 = ??
For mass sample use 0.750 for percent CrCl3 in the "removed" sample; use 1.75 if you want the percent in the original sample. The way you have the worded the problem (you have two samples) I can't tell which percent you want.