Organic Chemistry Structures of Organic Compounds

HhνBr 22 BrInitiationendothermicBrHH HBrSTEP 1 Propagation+HH Br+ Br 2 + Br STEP 2endothermicexothermicnet reaction exothermic2 BrBr 2TerminationH + HHH+BrBrLet’s look at a simpler systemCH 4 + Cl 2 → CH 3 Cl + HCl ∆H rxn = -104 kJ mol -11) Cl 2 → 2 Cl • ∆H 1 = +243 kJ mol -12) Cl • + CH 4 → CH • 3 + HCl ∆H 2 = +4 kJ mol -13) CH • 3 + Cl 2 → CH 3 Cl + Cl • ∆H 3 = -108 kJ mol -1But for brominationCH 4 + Br 2 → CH 3 Br + HBr ∆H rxn = -34 kJ mol -11) Br 2 → 2 Br • ∆H 1 = +192 kJ mol -12) Br • + CH 4 → CH • 3 + HBr ∆H 2 = +66 kJ mol -13) CH • 3 + Br 2 → CH 3 Br + Br • ∆H 3 = -100 kJ mol -1