Energy Change Q's
Hello,
I've been pondering over these for a while now and still can't seem to get anywhere, any help would be appreciated.
1) When 1g of ethanol undergoes complete combustion, 29.8kJ of heat energy is given out. How much heat would be given out for one mole of ethanol?
I figured: C2H5OH + 3O2 --> 2CO2 + 3H20
3231kJ + 1488kJ --> 2972kJ + 2778kJ
4719 - 5750 = -1031kJ/mol
One mole C2H5OH = 46g, 1g = 29.8kJ therefore -1031/46 should equal 29.8...it doesn't it equals -22.4kJ.
Where have I gone wrong?
2) When sulphur is burnt in oxygen it forms sulphur dioxide. Calculate the heat given out when 1.6g of sulphur is burnt.
S + O2 --> SO2 Energy Change = -297kJ/mol
I thought perhaps -297 x 20 would work?
Any help is appreciated, thanks.
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