Under what conditions can ammonia be oxidized to NH4NO2 ?
The Ber. ref. from Hoppe-Seyler describes it. Namely, strong solutions of H2O2 with a few drops of NH4OH or solutions of ammonium carbonate (with or
without NaOH or Na2CO3) can be let to stand 24 hours without any nitrite formation occurring. But upon longer standing, even with a small amount of
hydroxide then nitrite forms. Nitrite also forms when a dilute solution of H2O2 is mixed with NH4OH and a little Na2CO3 and is evaporated over pure
conc. H2SO4 with a bell jar.
H2O2 forms (even in very dilute solutions) nitrite very rapidly, if the H2O2 solution is mixed with a few drops of NH4OH and a little NaOH or Na2CO3,
and this then boiled in a retort to a very small volume. They suggest this nitrite formation as a demonstration experiment because it is very quick to
do, and then after acidification of the colorless liquid with H2SO4, the HNO2 can be nicely be proven to be present.
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