Calculate the percentage of water of hydration in barium chloride crystals (the atomic weight of Ba is about 137.4 g/mol)?

1 Answer
Jul 15, 2018

14.75%

Explanation:

You'll need to start off by knowing the formula of the barium chloride crystals, which is barium chloride dihydrate, BaCl22H2O. From the formula, you'll notice that there are 2 moles of H2O for every mole of the hydrate, BaCl22H2O.

When the 1 mole of hydrate crystals are heated, you will be left with 1 mole of the anhydrous crystal (BaCl2) and 2 moles of H2O, like this:

BaCl22H2OBaCl2+2H2O

To calculate the percentage of water of hydration, we'll need to find the molar mass of water (H2O) and hydrate crystal (BaCl22H2O).

molar mass H2O=2(1.01)+16.00=18.02 g/mol

molar mass BaCl22H2O=137.4+2(35.45)+2[2(1.01)+16.00]=244.34 g/mol

We can then proceed to calculating the percentage of water of hydration in barium chloride crystals:
Percentage of water of hydration=2×18.02244.34100%=14.75%