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Maharg
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Homework Statement
Consider an unknown solid containing BaCl2. 2H2O (MW = 244.26296). When the unknown is heated to 160 °C for 1 h, the water of crystallization is driven off:
BaCl2.2H2O(s) ---> BaCl2(s)+ 2 H2O(g)
A sample originally weighing 1.9226 g weighed 1.5647 g after heating. Calculate the weight percent of Ba (MW=137.327) in the original sample. BaCl2: MW=208.2324; H2O: MW=18.0153
Homework Equations
The Attempt at a Solution
I think I'm missing something with the water, but I'm not sure how to work it in.
I figured out mol of BaCl2*2H20
1.9226 g / 244.26296 g/mol = 7.8710 mmol
Calculated moles of BaCl2
1.5647 g/208.2324 g/mol = 7.514 mmol
Converted this to moles Ba
7.514 mmol * 137.327 g/mol = 1.0319026 g
Divided this by original weight to obtain w/w %
1.0319 g/1.9226 g = 53.67 %
This is not the right answer.