The density of 95% by mass of sulphuric acid, H2S04 is 1.84 g ml-1. Calculate the morality of H2SO4.

Answer 1

Not sure if you are asking to calculate the molarity or the molality (but not morality).

If we have 1 liter (1000 ml) of solution, then we have ...

1000 mls x 1.84 g / ml = 1840 g of solution

mass of H2SO4 = 1840 g x 95% = 1748 g H2SO4

moles H2SO4 = 1748 g x 1 mole / 98 g = 17.8 moles H2SO4

Molarity (M) = 17.8 moles / 1 L = 17.8 M

If you want the molality (m), subtract the mass of H2SO4 (1748 g) from the total mass (1840 g) to get mass of solvent. Convert that mass to kilograms. Finally, divide moles H2SO4 (17.8) by kg of solvent. Recall that molality (m) is moles of solute / kg of solvent.