Formation of ammoniacal silver may occur from:
(1) mixing silver nitrate with ammonium hydroxide
(2) reacting ammonia gas with elemental silver
Recommendations:
(1) Sources of ammonia and silver should be kept widely separated.
(2) The risk of an explosive increases with prolonged contact. Silver nitrate should not be left in an ammonium solution for more than 2 hours.
(3) A solution of ammoniacal silver that dries out will become an explosive.
(4) Store the solution in plastic bottles and not in glass. This is safer in the event that there is an explosion.
Disposal of an ammoniacal silver solution:
(1) Dilute the solution 1 part in 14 parts distilled water.
(2) Slowly add 5% hydrochloric acid until the pH is 2.0 The solution should be chilled with ice if it becomes warm.
(3) Silver chloride should precipitate out at the low pH. This can be filtered out of solution.
(4) The filtered solvent is then neutralized with sodium bicarbonate and disposed of.
