Aqua Ammonia Solution 4%
From Wikipedia, the free encyclopedia
Ammonium hydroxide, although it doesn’t exist as an isolatable chemical compound, is a name sometimes given to an aqueous solution of ammonia. Aqueous solutions of ammonia are sometimes referred to as ammonia water or aqua ammonia.
In aqueous solution, ammonia deprotonates some small fraction of the water to give ammonium and hydroxide ions according to the following equilibrium:
NH3 + H2O NH4+ + OH-
With a base ionization constant (Kb) of 1.8×10-5, in a 1M ammonia solution about 0.42% of the ammonia will gain protons to become ammonium ions (equivalent to a pH of 11.63).
Aqueous ammonium hydroxide can also dissolve various metal oxides and hydroxides, such as copper(II) hydroxide to form ammine complexes. In such cases, the active agent is the ammonia, not the hydroxide salt. Solutions of ammonium hydroxide can also dissolve reactive metals such as aluminum and zinc, with the liberation of hydrogen gas. When ammonium hydroxide is mixed with dilute hydrogen peroxide in the presence of a metal ion, such as Cu2+, the peroxide will undergo rapid decomposition.
Aqua Ammonia solution is commonly used for cleaning as an additive to glass cleaners.