63 - Chemical equilibrium in gaseous reactions

Abstract

This chapter describes the chemical equilibrium in gaseous reactions. For homogeneous reactions in the gas phase, it is more convenient to measure the pressures of the mixture of gases than to measure their concentrations in moles per cubic decimeter. For mixtures of gases in equilibrium, the concentrations of the gases can be expressed in terms of their pressures. When a gaseous reaction forms an equilibrium mixture, the total pressure of the mixture of gases is equal to the sum of the partial pressures. As the partial pressure of a gas is proportional to the number of moles of that gas, the relative numbers of moles of the gases are proportional to their partial pressures. Thus, the composition of an equilibrium mixture can be expressed in terms of the partial pressures of the gases. The effect of increasing the pressure on a gaseous equilibrium is equivalent to reducing the volume to the gaseous mixture.