Sulfuric acid, H2SO4, is sold as a 36% aqueous solution.

Question

What is this concentration in
A. Molality
B. Molarity
C. The Mole Fraction

Please and thank you. :)

Answer 1

You must have the density to answer the question. I have my handy dandy qual book I used about 60 years ago and it lists 36% H+2SO4 as having density of about 1.27 g/mL. You can't find tables like that in qual? books these days mostly because there aren't any qual books anymore. In fact most schools have done away with qual and replaced it with a second half of freshman chemistry but that's a band aid. Enough of my soap box and to the question.
1.27 g/mL x 1000 mL x 0.36 x (1/molar mass H2SO4) = mols/L = M = part b.

(Note: 1.27 g/mL x 1000 is the mass of 1 L of the solution, that times 0.36 is the mass of H2SO4 in that solution and that times 1/molar mass H2SO4 gives mols H2SO4/L which is M.)

part a.
You have moles from above. Divide by kg solvent. Find solvent by mass soln - mass H2SO4.

part c.
mols H2SO4 you have.
mols H2O = grams H2O/molar mass H2O
XH2SO4 = nH2SO4/total mols.