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what is the percentage of water in the hydrate cocl2 • 6h2o? show your work

You need the periodic table. Get the molar mass for each one. C is 12, O is 16, 2Cl is 71 (35.45 x 2), H2O is 18 x 6 of them is 108. Add them up and you get 207 g/mol. What is the percentage of water? Since you have 6 water molecules, and it is equal to 108, you simply divide 108 and 207. You get a decimal. Multiply it by 100%. You'll get 52.17%

The molecular mass of CoCl2 = 129,84 g/mol
The molecular mass of CoCl2+6H2O = 129,84+6*18 = 237,84 g/mol

And 129,84 = 129,84*100/237,84 = 54,59 % by mass.

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