Step-by-step explanation:
Molar mass is the the mass of one mole of a substance and is expressed in g/mol. Gold atomic mass is 196.96657, chlorine has 35.453. Hence, molar mass of AuCl3= atomic number of Gold + atomic mass of chlorine × (number of atoms of chlorine in AuCl3). Molar mass of AuCl3 = 196.96657 + (35.453 × 3).