Question

Find the molarity of the following solutions: Molarity = mole/Liters 1 liter - 1000 ml 1) 2.5 moles of NaCl is dissolved to make 0.050 liters of solution 2) 3.0 moles of AgCl is dissolved in enough water to make a 2.0 liter solution 3) 4.2 moles of lithium fluoride are dissolved in 2 liters of solution. 4) 18 grams of hydrochloric acid, HCl is dissolved to make 1 liter of solution.

Answer 1

Molarity of the solution = moles of solute/volume of the solution in L

(1) Molarity = 2.5 mol/0.050 L = 50 mol/L = 50 M

(2) Molarity of AgCl = 3.0 mol/2.0 L = 1.5 M

(3) Molarity of LiF = 4.2 mol/2 L = 2.1 M

(4) Number of moles of HCl = mass/mol.wt. = 18 g/(36.46 g/mol) = 0.493692 mol

Molarity of HCl = 0.493692 mol/1 L = 0.493692 M = 0.494 M