Hello. I am doing a chemistry problem but it is mainly mathematics Here it is. A little info that is useful to this problem. Molar mass is always an average, given by Molar Mass = (mass of isotope1 * abundance of isotope 1) + (mass of isotope2 + abundance of isotope 2) Masses of isotopes are always constant, they do not vary from place to place. So how do I solve this?