The normal boiling point of ammonia is -33.33 C. The boiling point of ammonia under 23.74 psi is -23.33 C. Suppose the pressure on the liquid ammonia at -23.33 C is suddenly dropped from 23.74 psi to 14.71 psi (1 atmosphere). What will happen? Calculate the entropy change of the universe per mole of ammonia for this event. The heat vaporization of liquid ammonia at -33.33 C is 327.4 cal/g while that at -23.33 C is 320.2 cal/g. The heat capacity of gaseous ammonia is 35.06 J/K mol while that of liquid ammonia is 80.80 J/K.