Question

Battery acid is 4.22 M aqueous H₂SO₄ solution, and has density of 1.21 g cm⁻³. What is the molality of H₂SO₄? H=1, S=32, O=16 (m=5.298 mol kg⁻¹)

Answer 1

I AM NOT SURE ABOUT MY ANSWER !!

Answer 2

This is a 4.22M solution. 1000cm³ of the solution contains 4.22 moles of H2SO4,

Molar mass of H2SO4 = 1x2 + 32 + 16x4 = 98,

Mass of H2SO4 in the solution = 4.22x98 = 413.56g.

Total mass of the solution = 1000x1.21 = 1210g,

Mass of water = 1210 - 413.56 = 796.44 g = 0.79644kg,

Molality = Moles of solute/ kg of solvent.

Hence Molality = 4.22/0.79644 = 5.3mol/kg