Response: a) 
b) 
Rationale:
When percentages are provided, we assume the total mass to be 100 grams.
Consequently, the mass of each element corresponds to its respective percentage.
a) Mass of Ba= 66.06 g
Mass of Cl = 34.0 g
Step 1: convert given masses into moles.
Moles of Ba =
Moles of Cl = \frac{\text{ given mass of Cl}}{\text{ molar mass of Cl}}= \frac{34g}{35.5g/mole}=0.96moles[/tex]
Step 2: To establish the mole ratio, divide each mole value by the smallest mole quantity obtained.
For Ba =
For O =
The ratio of Ba: Cl= 1:2
As a result, the empirical formula is 
b) Mass of Bi= 80.38 g
Mass of O= 18.46 g
Mass of H = 1.16 g
Step 1: convert given masses into moles.
Moles of Bi =
Moles of O=
Moles of H=
Step 2: For determining the mole ratio, divide each mole value by the smallest quantity of moles identified.
For Bi=
For O =
For H=
The ratio of Bi: O: H= 1:3: 3
Consequently, the empirical formula is 