Why Addition Reactions Proceed Thermodynamic Feasibility

The carbon-carbon rr bond is relatively weak, and the chemistry of the alkenes is governed largely by its reactions. The most common transformation is addition of a reagent A-B to give a saturated compound. In the process, the A-B bond is broken, and A and B form 

Recall that we can estimate the AH° of such reactions by subtracting the combined strength of the bonds made from that of the bonds broken (Section 3-4)  

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