The article gives a methodology for determining the direction of a reaction and the point where gaseous equilibrium exists, emphasising the minimum of the Gibbs function at chemical equilibrium. A new result is offered, Lewins' law on the effect of dilution and explicit formulae are given for some major reactions. The calculations involved can be readily performed with the aid of a computer programme. This approach is seen as particularly helpful for students of combustion processes who lack a chemistry background.
