Use bond energies to determine δhrxn for the reaction between ethane and chlorine. ch3ch3(g)+cl2(g)→ch3ch2cl(g)+hcl(g)

For this reaction to proceed, the following bond breaking should occur: 

*one C-H bond
* one Cl-Cl bond

After, the following bond formations should occur:
*one C-Cl bond
*one H-Cl bond

Now, add the bond energies for the respective bond energies which can be found in the attached picture. For bond formations, energy is negative. For bond breaking, energy is positive.

ΔHrxn = (1)(413) + (1)(242) + 1(-328) + 1(-431) = -104 kJ