Estimating pH of ammonium solutions containing weak Brønsted-Lowry bases

In secondary education and first year university students' chemistry textbooks, the chapters regarding calculations of pH for either a Brønsted-Lowry weak acid or weak base solution are taught as separate topics.

Students may be asked to calculate the pH of a 0.1 M ammonium chloride solution and in another problem calculate the pH of a 0.1 M sodium benzoate solution. In one textbook there is a limited discussion, without calculations, about the pH of a salt solution containing a Brønsted-Lowry weak acid and weak base in which the K_a and K_b are equivalent, eg ammonium acetate.