Microscale Synthesis of Hexaamminechromium(III) Nitrate Using Liquid Ammonia Generated in the Laboratory

The previously published synthesis of hexaamminechromium(III) nitrate using liquid ammonia as the solvent is an experiment that can be used in an advanced inorganic chemistry laboratory as an example of using a nonaqueous inorganic solvent in inorganic synthesis. Potential hazards are associated with the amount of liquid ammonia used in the experiment and the need to store this corrosive material (which is also expensive to purchase). These problems can be eliminated or reduced by performing this experiment on a microscale level and generating the small amount of ammonia needed directly in the laboratory at the time of the experiment. The ammonia is generated by heating concentrated ammonium hydroxide and condensing the ammonia vapors into the reaction vessel.