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





Doubling the concentration of HI molecules doubles the number of molecules available for collision, and independently doubles the rate at which each one collides with a neighbor. The result is a second-power dependence, and a second-order reaction.

At equilibrium, synthesis and breakdown of HI are exactly in balance. The forward and reverse reaction rates are equal, and





This is the equilibrium-constant expression for the HI reaction. It tells us that regardless of whether the absolute concentrations are high or low, at equilibrium the ratio of products to reactants will be the same.

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