The molar mass of AuCl3 is 303.33 grams/mole. AuCl3 is the chemical formula for the substance known as gold(III) chloride or auric chloride. Gold(III) chloride is a common compound of gold.
Molar mass is the number of grams per mole of a substance. To calculate the molar mass of a substance, the number of each atom of an element is multiplied by the atomic weight of that element. The atomic weight of an element is found on the periodic table of elements, and the number of atoms is in the chemical formula itself. For example, AuCl3 contains one atom of gold and three atoms of chlorine.