Question

What would be the resulting molarity of a solution made by dissolving 17.8 grams of LiF in enough water to make a 915-milliliter solution? Show all of the work needed to solve this problem.

Answer 1

First, determine the amount of substance in moles by dividing the given amount in grams by the molar mass. 
              17.8 grams LiF x (1 mole / 25.94 grams LiF) = 0.686 moles LiF
Divide this amount of substance by the volume of the solution in liters.
                           molarity = 0.686 moles LiF / 0.915 L sol'n
The molarity is therefore, 0.75 M.