In order to find the molar mass of a compound using the periodic table, we need to look for the mass of the individual elements that compose this compound, and in the case of Ca(NO3)2, we have:
Ca = 40 grams
N = 14 grams, but we have 2 = 28 grams
O = 16 grams, but we have 6 = 96 grams
Now we add all these values:
40 + 28 + 96 = 164.09g/mol this is the molar mass of Ca(NO3)2
