Question

A solution of H2SO4(aq) with a molal concentration of 5.25 m has a density of 1.266 g/mL. What is the molar concentration of this solution?

Answer 1

molality number of moles of solute per kilogram of solvent
5.25 mol/1kg solvent

1) you calculate how many g of solute you have in 5.25 mol
5.25 mol H2SO4 x 98.07g /1 mol= "A" g of H2SO4

2) then you add that grams to the grams of solvent to get the grams of solution
"A" g of H2SO4 + 1000 g solvent = "B" g solution

3) convert the g of solution to ml then to L of solution
"B" g solution x 1ml / 1.266 g = "C" ml of solution= "C" /1000 = "D" L solution

4) divide the moles of solute by the volume of solution in liters to find the molarity
5.25 mol H2SO4 / "D" L solution = M