Here's how to calculate the grams in one mole of Bromine trifluoride (BrF3):

1. Find the Molar Mass:

* Bromine (Br): 79.904 g/mol

* Fluorine (F): 18.998 g/mol

* BrF3: (79.904 g/mol) + (3 * 18.998 g/mol) = 136.900 g/mol

2. One Mole = Molar Mass:

One mole of any substance has a mass equal to its molar mass. Therefore, one mole of Bromine trifluoride weighs 136.900 grams.