Is chemical bond formation an exothermic or a endothermic process?
Bond formation is an EXOTHERMIC process. Bond breaking (i.e. fission, cleavage) is an ENDOTHERMIC process.
We recognize that the combustion of methane is an exothermic process:
(Normally, we would write
In this combustion process, we have to break strong
WE can go even further than this and approach the problem with individual bond energies. Tables of bond energy data exist that list the energy necessary to break particular bonds, i,e.
When you do a summation from these data, with bonds broken positive, and bonds formed negative, you can get an answer that is precisely the same as the experimental value. This same result from experiment and tabulated data persuades us that the treatment is valid.