You’ve probably heard that you should never mix household bleach with ammonia. With a little research I’ve discovered the reason why. Bleach is a solution of sodium hypochlorite, and sodium hypochlorite and ammonia react to form a number of products, depending on the temperature, concentration, and how they are mixed. To be more precise, in bleach sodium hypochlorite (NaOCl) dissociates into its ionic components
NaOCl → Na+ + OCl-
OCl- in turn reacts weakly with water to form:
OCl- + H2O → H+ + Cl- + HOCl, in which the H+ + Cl- portion is just hydrochloric acid.
Stronger reactions are:
NH3 + OCl- → OH- + NH2Cl
NH2Cl + OCl- → OH- + NHCl2
NHCl2 + OCl- → OH- + NCl3