Determine the mass fractions of chemical elements in sulfuric acid and express as a percentage.

The mass of sulfuric acid (H2SO4) = 98 grams / mol and this is 100 percent. From here, by proportion, we can find the mass fraction of sulfur: 98 grams – 100%, and 32 grams – X; X = 32 * 100/98 = 32.65%. Mass fraction of oxygen: 98 grams – 100%, and 64 grams – X; X = 64 * 100/98 = 65.30%. Mass fraction of hydrogen: 98 grams – 100%, and 2 grams – X; X = 2 * 100/98 = 2.04%. When checking the problem, we add the mass fractions of all elements together and the sum should get 100%: 2.04 + 65.3 + 32.65 = 100%