14. Chemical Equilibrium   Previous PageNext Page
       Equilibrium and Second-Order Processes

Very few chemical reactions are spontaneous decompositions of molecules, with first-order kinetics and equilibium as in the crabapple war. First-order kinetics are encountered more commonly in radiochemistry and the decay of atomic nuclei. Most chemical reactions occur when two or more molecules or ions collide, so the rates of reaction depend simultaneously on the concentrations of more than one substance.


In the hydrogen-iodine reaction,

(g) + 2HI (g)

one molecule of hydrogen gas must interact with one molecule of iodine vapor for chemical reaction to take place.

  Page 15 of 47 HomeGlossary