Calculate the empirical formula for each compound.
2.677 g ba, 3.115 g br

Element  - Ba

Moles = mass / (molar mass)

Mole ratio

Element  - Br

Moles = mass / (molar mass)

Smallest is 0.0195 mol

Mole ratio

Empirical formula

So, The empirical formula is

We divide mass by molar mass to get moles in the first step and then we select the least answer from it and divide them all. The whole number which we get becomes the subscript of the Empirical formula.