In what unit is formula mass expressed?
F=ma
Formula mass, also known as molar mass or molecular weight, is expressed in atomic mass units (amu) or grams per mole (g/mol).
To calculate the formula mass of a compound, you need to sum the atomic masses of all the atoms present in the compound. The atomic masses of elements can be found on the periodic table.
For example, let's calculate the formula mass of water (H2O):
- The atomic mass of hydrogen (H) is approximately 1 amu.
- The atomic mass of oxygen (O) is approximately 16 amu.
To get the formula mass of water, you would add the atomic mass of two hydrogen atoms to the atomic mass of one oxygen atom:
(2 * 1 amu) + (1 * 16 amu) = 18 amu
So, the formula mass of water (H2O) is 18 amu or 18 g/mol.
Remember that the formula mass is calculated to determine the quantity of a substance in moles, which is needed for various chemical calculations.