Final answer:
The mass of one mole of Ba(NO₃)₂ is approximately 199.331 g/mol.
Step-by-step explanation:
The molar mass of Ba(NO₃)₂ can be calculated by summing the atomic masses of all the elements in the compound. The atomic mass of Ba is 137.327 g/mol, the atomic mass of N is 14.007 g/mol, and the atomic mass of O is 15.999 g/mol. There are two nitrate ions in the compound, so we need to multiply the atomic mass of NO₃ by 2.
Calculating the molar mass:
(1 x Ba) + (2 x NO₃) = (1 x 137.327 g/mol) + (2 x (14.007 g/mol + 3 x 15.999 g/mol)) = 137.327 g/mol + 62.004 g/mol
= 199.331 g/mol.
Therefore, the mass of one mole of Ba(NO₃)₂ is approximately 199.331 g/mol.