1) Molar mass. In order to find the molar mass of a compound, we have to look for each molar mass of the elements in the compound and multiply by its subscript.
Phosphorus (P): 30.974
Bromide (Br): 79.905
MM PBr5 = 30.974 + (5*79.905) = 430.499.
The answer is 430.6
