S.I Unit of Molar mass is gram per mole and it is represented as g/mol.
Atomic Mass of oxygen (O) = 16 g
Atomic Mass of sulphur (S) = 32 g
Atomic Mass of barium (Ba) = 137 g
Molecular mass of = 137 +32 + 16(4) =233 g/mol
Relative molar mass is defined as the smallest mass unit of a compound with one twelfth of the mass of one carbon – 12 atom.