Question

A commercial available sample of hydrogen sulphate is 25%H2SO4 by mass(density=1.10g mol^-1) calculate molality and normality​

Answer 1

25% H2SO4 ie 25g H2SO4 in 100g solution

Density = 1.1g/ml

Volume of solution = Mass/Density = 100/1.1 = 91ml

No. of moles of H2SO4 = Given mass/molar mass = 25/98 = 0.26 mol

Molarity = no. of moles of H2SO4/Volume of solution in L = 0.26/0.091 = 2.86 mol/L

n factor = 2

Normality = M X V = 2.86 x 2 = 5.72

Mass of solvent = 100 - 25 = 75g

Molality = no. of moles of H2SO4/mass of solvent in kg = 0.26/75 = 0.003 mol/Kg