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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: WashableMarker on October 12, 2005, 09:41:16 PM

Title: Combustion of glucose
Post by: WashableMarker on October 12, 2005, 09:41:16 PM

Okay, this seems basic enough, but the textbook is throwing me for a bit of a loop... I understand that you have to figure out how much energy is contained in the bonds of glucose [9496kJ/mol], but the book is suggesting that...

[delta]H = kJ/mol C₆H₁₂O₆ / [2870 kJ/mol]
so... 9496kJ/mol / 2870 kJ/mol ?

This isn't making sense to me, and I'm getting something like 3.3, which is... way out there. Can anybody shed some light on this "other" method, and is there some secret meaning behind 2870kJ? Or, is the textbook completely wrong and I should instead calculate the energy released in the breaking of bonds and the energy absorbed when forming the products?

Thanks!

Title: Re:Combustion of glucose
Post by: Donaldson Tan on October 13, 2005, 07:49:13 AM

what are you calculating?

Is it:
1. the sum of bond energy of each bond in glucose?
2. how much energy is liberated when glucose is oxidised in the human body?