To calculate the molar mass of Ba NO3 2, we need to find the molar mass of each element in the compound and then add them together.1. Barium Ba : 137.33 g/mol2. Nitrogen N : 14.01 g/mol3. Oxygen O : 16.00 g/molThe formula for Barium nitrate is Ba NO3 2, which means we have:- 1 Barium atom- 2 Nitrogen atoms since there are 2 NO3 groups - 6 Oxygen atoms since there are 2 NO3 groups with 3 Oxygen atoms each Now, we can calculate the molar mass: 1 137.33 g/mol + 2 14.01 g/mol + 6 16.00 g/mol = 137.33 + 28.02 + 96.00 = 261.35 g/molThe molar mass of Ba NO3 2 is 261.35 g/mol.