1. Assume a 100 g Sample

* This makes the calculations easier, as the percentages directly translate to grams.

* We have 85.3 g BaCl₂ and 14.7 g H₂O.

2. Convert Grams to Moles

* BaCl₂: (85.3 g BaCl₂) / (208.23 g/mol BaCl₂) = 0.409 moles BaCl₂

* H₂O: (14.7 g H₂O) / (18.02 g/mol H₂O) = 0.816 moles H₂O

3. Find the Mole Ratio

* Divide the number of moles of each component by the smallest number of moles (0.409 moles BaCl₂).

* BaCl₂: 0.409 / 0.409 = 1

* H₂O: 0.816 / 0.409 = 2

4. Write the Formula

The mole ratio tells us that for every 1 mole of BaCl₂, there are 2 moles of H₂O. Therefore, the formula of the hydrate is:

BaCl₂ ⋅ 2H₂O