Ask A Scientist Chemistry Archive

name         Konnie
status       educator
grade        9-12
location     NM

Question -   What is the chemical make up of ammonia and if it is
as dangerous as proclaimed why do so many people use it for daily
household cleaning and also, does amonia disinfect? I live in New
Mexico and mice in New Mexico are known to carry disease and it is
recommended that ammonia can kill the germs from these affected mice
on contact- how is that possible if ammonia does not have
disinfecting capabilities? Thank-you
There are several questions here: 1. The chemical formula/structure of
ammonia is NH3, with the three hydrogens forming the base of a trigonal
pyramid and a pair of electrons forming the apex of the pyramid. Like all
chemical substances ammonia can be toxic, but it is also has a very
irritating, characteristic odor. As a result, one would usually make a
hasty retreat from a source of ammonia unless trapped. Historically,
ammonia has been the active ingredient in "smelling salts". When a person
is faint, a whiff of ammonia quickly causes an awakening reaction because
of the irritating smell. Ammonia has disinfecting properties, partly
because it raises the pH. The increased alkalinity kills many types of
microbes. A note of safety: ammonia should NEVER be used in combination
with household bleach. The combination of the two produces chloramines, in
which 1,2, or all 3 of the hydrogens are replaced by chlorine atoms having
the formula/structure (NH2Cl, NHCl2, and NCl3). These substances are much
more toxic, and irritating than ammonia or bleach, each one by itself. In
swimming pools that are not properly balanced, it is these compounds that
produce eye irritation.

Vince Calder
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