Calculating Percentage Mass

Q1: What percentage of H2O is hydrogen?

Mass of H2O is 18
Mass of hydrogen in H2O is 2.
2/18*100=11.1% (to 3s.f.)

Calculating Percentage Mass

Q2: What percentage of NH3 is hydrogen?

Mass of NH3 is 17
Mass of hydrogen in NH3 is 3.
3/17*100=17.6%% (to 3s.f.)

Calculating Percentage Mass

Q3: What percentage of SO3 is sulfur?

Mass of SO3 is 80
Mass of sulfur in SO3 is 32
32/80*100=40% (to 3s.f.)
Return to The Top of The Page