How many milliliters of a 0.200M AgNO3 solution are required to preccipitate most of the Cl^- ions from a solution containing 0.855 g of NaCl?
NaCl + AgNO3 = AgCl + NaNO3
moles NaCl = grams/molar mass
mols AgNO3 = moles NaCl
M AgNO3 = mols/L
Solve for L.