Physical Chemistry Chapter 7 The phase rule The difference between(a)a single-phase solution, in which the composition is uniform on a microscopic scale, and(b)a dispersion, in which regions of one component are embedded in a matrix of a second component3 The Phase Rule (a) (b) The difference between (a) a single-phase solution, in which the composition is uniform on a microscopic scale, and (b) a dispersion, in which regions of one component are embedded in a matrix of a second component. Physical Chemistry Chapter 7