Calculate the formula unit mass of the following compounds

**Formula unit mass:** The formula unit mass of a substance is the sum of the atomic masses of all atoms in a formula unit of a compound. The term â€˜formula unitâ€™ is used for those substances which are made up of ions.

Formula unit mass of ZnO = Atomic mass of zinc + atomic mass of oxygen

= 65 + 16 = 81u

Formula unit mass of Na2O = 2X 23 +16 =46 + 16 =62u

Formula unit mass of K2CO3 = 2X39 + 12 + 2X16 = 78 + 12 + 32 = 122 u