Molar mass is an essential concept in chemistry, representing the mass of one mole of a given substance. It is measured in grams per mole (g/mol) and determined by adding up the atomic masses of all atoms in a molecule.
To find out which compound has the greatest percent oxygen by mass, you need to consider both the number of oxygen atoms and the molar mass:
- Dinitrogen tetroxide (
N_2O_4"): The molar mass involves two nitrogen and four oxygen atoms.
- Aluminum oxide (
Al_2O_3"): The molar mass includes two aluminum and three oxygen atoms.
- Tetraphosphorus hexoxide (
P_4O_6"): Four phosphorus and six oxygen atoms determine its molar mass.
- Carbon dioxide (
CO_2"): The molar mass includes one carbon and two oxygen atoms.
By comparing them, you can identify that despite having fewer oxygen atoms, carbon dioxide's simple composition results in a higher percent oxygen by mass.