Question

The Molarity of sulphuric acid is 1.35M calculate its molality if the density of the solution is 1.03 g/cm3

Answer 1

Answer:

Explanation:

Since molarity of the solution is 1.35 M, it means the solution have 1.35moles of H2SO4 in 1000 ml of solution.

Mass of 1000 ml of solution = density x volume = 1.03 g cm-3 x 1000 cm-3 = 1030 g

Mass of H2SO4 in 1.35 mol of H2SO4 = 1.35 mol x 98 g mol-1 = 132.3 g

Mass of water (solvent) = 1030 g - 132.3 g = 897.7 g

Moles of water (solvent) = 897.7 g / 18 g mol-1 = 49.87 mol

Since, molality is the moles of solute in 1 Kg of the solvent, the molality of the solution is = (1.35 mol / 897.7 g) x 1000 g = 1.504 m