How do you calculate the atomic mass of a compound?

1 Answer


Well, if you want the molar mass, you add together the mass of every individual element in the compound. Compounds don't have an atomic mass.


For example in #H_2O#
Hydrogen (H) has a mass of 1.008
Oxygen (O) has a mass of 16.00

Since there is 2 hydrogen atoms in #H_2O# we add 1.008 twice or we can say 2(1.008)+16= 18.016

If you look up the mass of water it is 18.01528 g/mol.

You can use this method for any chemical compound.