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# How to do this CH5 question?

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Why bother with a post grad? Are they even worth it? Have your say! 26-10-2016
1. Very stuck on this... have no clue :/
2. 2H2O2(aq) 2H2O(I) + O2(g) this was the equation! 1dm3 under 2H2O2 and 20dm3 under O2
3. Yeah, we know that there's 20dm3 of O2, so we can calculate the moles of O2 because we know its volume and its molar volume at 25 degrees. n=volume/molar volume = n=20/24 = 0.83

In the equation, H202 is 2moles while o2 is 1 mole so 2:1 ratio. So moles of h2o2 is 0.83 x 2 = 1.67moles

The volume of h2o2 in the reaction is 1dm3 so c=n/v = 1.67/1 = 1.67mol dm3

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Updated: June 18, 2016
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