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) =
<em>-104 kJ</em>
I believe the charge is positive as losing an electron suggests that the atom lost a negative charge, leaving it with more positive than negative.
I haven't taken this in a few years very sorry if i'm wrong tho.