posted by cristy .
How many mL of a 0.217 M aqueous solution of ammonium fluoride, NH4F, must be taken to obtain 3.63 grams of the salt?
Start from calculating the molar mass of NH4F, F.
we need therefore, 3.63/F moles of ammonium fluoride.
The solution contains 0.217 M, or 0.217 moles in 1 litre.
which is 1000/0.217 ml mole^-1
hence volume required is
(1000/0.217 ml mole^-1)x (3.63/F moles )