What is the percent of phosphorus by mass in phosphoric acid,
H3PO4?
Use 1.008 g/mol for the molar mass of hydrogen, 16.00 g/mol
for the molar mass of oxygen, and 30.97 g/mol for the molar
mass of phosphorus.
Then divide the molar mass of P in the compound by the total molar mass of the compound. Then multiply by 100% to make it a percent instead of a decimal.
