The molar mass of barium nitrate is 261.32 g/mol. The chemical formula of this salt composed of barium and the nitrate ion is Ba(NO3)2. It exists as a white solid at room temperature.
To find the molar mass of Ba(NO3)2, determine the molar masses of all the atoms that form it. The molar mass of every atom can be looked up on the Periodic Table of the Elements. For barium nitrate, the atoms are barium, nitrogen and oxygen, and their molar masses are 137.3, 14.01 and 16 grams, respectively. Add the molar masses together: 137.3 + (2x14.01) + (6x16) yields 261.32 grams. The molar mass of barium nitrate is 261.32 grams.