Density and Molarity

Conc. sulphuric acid of density 1.84 g per cm³ contains 98% by mass ofsulphuric acid. What volume of the conc.acid should be diluted to prepare 250 cm³ of 0.10M solution ?


No. of moles of H2SO4 in the diluted solution = 0.1 *(250/1000) = 0.025 mol
No. of moles of H2SO4 in the conc. sulphuric acid = 0.025mol

Molar mass of H2SO4 = (1*2 + 32.1 + 16*4) = 98.1 g/mol
Mass of H2SO4 in the conc. sulphuric acid = 0.025 * 98.1= 2.4525 g

Since the conc. sulphuric acid used contains 98% by mass of H2SO4.
Mass of the conc. sulphuric acid = 2.4525 / 98% = 2.4525 * (100/98) = 2.5036 g

Volume of conc. sulphuric acid = 2.5036 / 1.84 = 1.36 cm³