|III. Gas-Phase Equilibria|
|III-1. Introduction and Background||III-2. Sample Problem||III-3. List of Problems||III-4. Simple Problems||III-5. Advanced Problems|
Gas-phase equilibria are important in a variety of environmental and industrial chemical situations. In general a gas or gases will exist in equilibrium with other gases or solids. In the atmosphere, nitrogen and sulfur oxides produced in combustion contribute to pollutants. In the Haber process, a major industrial process, manipulating the equilibrium conditions is the primary way to produce NH3 from N2 and H2. For information on how gas-phase reactions compare to other types of reactions, see the background document on chemical reactions.
In the simple problems, partial pressures are given to use in the equilibrium calculations. In more complicated problems you will often be given moles or grams of gas; or temperature, pressure or volume conditions might change shifting the equilibrium. In these cases use the ideal gas law.
The ideal gas law is: PV = nRTwhere: