What Is The Formula Unit Of Mass?

Answer: The formula mass is determined by summing the masses of each atom in the compound’s formula. The ions can be regarded as atoms to determine the formula mass since a valid formula is electrically balanced (with no net electrons gained or lost).

For example:

Na2CO3

2Na + 1C + 3O = (2 × 23) + (1 × 12) +(3 × 16) = 46 + 12 + 48 = 106 u.