Question

How many kilojoules of energy are released from the carbon carbon single bonds when glucose (C6H12O6) is burned???

thanks

Answer 1

In a six-carbon chain, there are 5 C-C bonds. When those bonds break during combustion, energy is absorbed, <b>not</b> released.
The energy released is due to the formation of C=O bonds in CO2 and H-O bonds in H2O.
Calculating the NET energy released must take into account the energy absorbed for breaking bonds and energy released by the formation of new bonds.