NITROUS ACID химические свойства, назначение, производство
Описание
Nitrous acid (molecular formula?HNO2) is a weak
and monobasic acid known only in solution and in the
form of nitrite salts. Nitrous acid rapidly decomposes
into nitrogen oxide, nitric oxide and water when in
solution:
2HNO2 ? NO2 + NO+H2O
It can also decompose into nitric acid and nitrous
oxide and water.
4HNO2 ? 2HNO3 +N2O +H2O
Nitric acid (HNO3), also known as “aqua fortis”
and “spirit of nitre”, is a highly corrosive and toxic
strong acid that can cause severe burns. It is colorless
when pure and a slight yellow when “glacial”. Older
samples tend to acquire a yellow cast due to the accumulation
of various oxides of nitrogen. If the solution contains more than 86% nitric acid, it is referred to as
“fuming nitric acid”.
Химические свойства
A weak acid occurring only in the form
of a light-blue solution.
Физические свойства
Pale blue solution; stable only in solution; weak acid, Ka 4.5x10-4.
Использование
Formation of diazotizing compounds by reaction with primary aromatic amines, source of nitric
oxide.
Использование
Nitrous acid is a nitrogen oxoacid. It is a conjugate acid of a nitrite. It (as sodium nitrite) is used as part of an intravenous mixture with sodium thiosulfate to treat cyanide poisoning. There is also research to investigate its applicability towards treatments for heart attacks, brain aneurysms, pulmonary hypertension in infants, and Pseudomonas aeruginosa infections.
Подготовка
Nitrous acid may be obtained in solution by adding a strong acid to nitrite; e.g., adding hydrochloric acid to sodium nitrite solution:
H+ + NO2 ˉ → HNO2.
Определение
A weak
acid known only in solution, obtained by
acidifying a solution of a nitrite. It readily
decomposes on warming or shaking to nitrogen
monoxide and nitric acid. The use
of nitrous acid is very important in the
dyestuffs industry in the diazo reaction: nitrous
acid is liberated by acidifying a solution
of a nitrite (usually sodium nitrite) in the presence of the compound to be diazotized.
Nitrous acid and the nitrites are normally
reducing agents but in certain
circumstances they can behave as oxidizing
agents, e.g. with sulfur dioxide and hydrogen
sulfide.
Опасность
Rapidly forms nitric oxide and nitric acid in water; [Merck Index] A strong oxidizer; Causes burns; Highly toxic by ingestion and inhalation.
Профиль безопасности
Mutation data reported.
Flammable by chemical reaction; a powerful oxidizer. Explodes on contact with
phosphorus trichloride. Reacts violently
with PH3 and Pcb. Reactions with l-amino-
5-nitrophenol, ammonium
decahydroborate(2-), hydrazine (product is
hydrogen azide) may give explosive
products. Incompatible with anilines (e.g., 4-
bromoahe , 2-chloroaniline, 3-
chloroaniline, 2-nitroadine, 3-nitroaniline,
4-nitroaniline, aniline ), semicarbazone, silver
nitrate. When heated to decomposition it
emits hghly toxic fumes of NOx. See also
NITRIC OXIDE.
NITROUS ACID препаратная продукция и сырье
сырьё
препарат