Question

A solution of H2SO4(aq) with a molal concentration of 6.25 m has a density of 1.300 g/mL. What is the molar concentration of this solution?

Answer 1

A solution of H2SO4(aq) with a molal concentration of 6.25 m has a density of 1.300 g/mL. What is the molar concentration of this solution?

Mola concentration = mol of solute / volume of solution

assume:

n = 6.25 moles of solute, so

mass of H2SO4 = mol*MW = 6.25*98 = 612.5 g of H2SO4

note that this is in 1 kg of solvent, that is 1 kg of water, or 1000 g of water

total mass = 612.5 + 1000 = 1612.5 g

Now...

Density = mass / volume of solution

Vol = mass/D = 1612.5 / 1.3 = 1240.384 mL = 1.240384 L

therefore

M = mol / V = 6.25 mol /1.240384 Liters = 5.0387 M