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? Molar concentration=M?

Answer 1

Molarity = moles H2SO4 / liter of solution

Molality = moles H2SO4 / kg H2O

5.25 m = 5.25 mols H2SO4 / kg water

molar mass H2SO4 = 98.1 g / mol

5.25 mol / kg water = 5.25 mol x 98.1 g / mol = 515 g H2SO4 / 1000 g water

Total mass = 515 g + 1000 g = 1515 g of solution

Volume of solution = 1515 g x 1 ml / 1.266 g = 1197 mls = 1.197 L

We now have the moles of H2SO4 (5.25) and the liters of solution (1.197)

Molarity (M) = moles H2SO4 / L

Molarity = 5.25 mol / 1.197 L

Molarity = 4.39 M