Is ammonium hydroxide the same as concentrated ammonia?

1 Answer
Jun 5, 2016

Answer:

You mean #NH_4OH#. And yes this is the same as concentrated ammonia.

Explanation:

Ammonia, #NH_3#, is a water like gas, that has substantial solubility in water. Once dissolved in water, it undergoes an acid base equilibrium to some extent:

#NH_3(aq) + H_2O rightleftharpoons NH_4^+ + HO^-#

The equilibrium lies strongly to the left; that is most of the ammonia, while still a water solvate, is the free base.

When we buy concentrated ammonia, I think Fisher sell it as #"ammonium hydroxide"#, i.e. #NH_4OH#; a better representation would be as #NH_3*H_2O#.

When we want to use pure ammonia as a solvent, we must buy a cylinder of ammonia gas under pressure. With a dry ice/acetone condenser, the #-78# #""^@C# temperature condenses the ammonia gas (#"boiling point ="-33.3# #""^@C#), and allows us to perform reactions in this solvent.

So to conclude ammonia gas, a pungent colourless gas, is DISTINCT from aqueous ammonia, a solution of ammonia in water. Ammonia fumes will bring tears to your eyes.

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