DD has been stuck for this for a while and i'm totally useless at anything like this, she is much more intelligent than me not wanting to feel totally helpless, i mentioned to her that there are some people on here that may help. She writes:
'For: methanol, ethanol, propanol, butanol, pentanol and hexanol, I need to find the theoretical energy transfer if they were burned in air (oxygen).
This requires balancing the equations which I have already done but when it comes to the actual calculations, my results have no pattern and aren't all negative numbers (as they should be as they are exothermic.) I know they are wrong but I can't see where I am making the mistakes. If someone could explain, do one example for me, I would be so grateful, here's what you need to know:
The equation: Alcohol + Oxygen ---> Carbon dioxide + Water
Bond values (Kj/mol)
H-C - 413
C-C - 347
O-C - 336
O=O - 498
C=O - 805
O-H - 464
Thanks to anyone who can help as I always get the wrong answer (no pattern and some are positive - not exothermic.) '
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HARD chemistry CW - help needed!
27 replies
Chocolatechick · 27/03/2007 19:43
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