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what is molar mass ?
The molar mass is the mass of one mole of a substance. To find the molar mass, add the atomic masses (atomic weights) of all of the atoms in the molecule. To find the atomic mass for each element by using the mass given in the Periodic Table or table of atomic weights. Multiply the subscript (number of atoms) times the atomic mass of that element and add the masses of all of the elements in the molecule to get the molecular mass. Molar mass usually is expressed in grams (g) or kilograms (kg).

Example: Find the molar mass of sodium carbonate, Na2CO3.
Na:          2    x     23.0    =   46.0
C:            1    x     12.0    =     12.0
O:            3    x     16.0    =     48.0
           
molar mass  =    106.0 g/mole


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