Question

How are chemical bonds related to energy?

Answer 1

The breaking of bonds REQUIRES energy........

Explanation:

And the making of chemical bonds RELEASES energy.

And for a simple combustion reaction:

`CH_4(g) + 2O_2(g) rarr CO_2(g) + 2H_2O(l) + Delta`

Now in this reaction, we have to break strong `C-H` and `O=O` bonds, but WE MAKE even stronger `O=C` and `O-H` bonds. The balance, the energy difference is released as energy that can be used to do work. And using standard tables of bond enthalpies, we can calculate the energy evolved by the reaction, and this AGREES very precisely with the experimental value.