Figure 10.4 Potential energy diagram for the dissociation of a chlorine molecule
into chlorine atoms.
4) The energy of activation for a gas-phase reaction in which radicals combine
to form molecules is usually zero.2 CH 3 • CH 3 –CH 3 ∆H° = – 368 kJ mol–1
(∆H° = 368) Eact = 0 kJ mol–1
Figure 10.5 Potential energy diagram for the combination of two methyl radicals to
form a molecule of ethane.
10.5C REACTION OF METHANE WITH OTHER HALOGENS:
- The reactivity of one substance toward another is measured by the rate at which
the two substances react.
- Fluorine is most reactive –– so reactive that without special precautions mixtures