ChemicalBook CAS DataBase List 7782-77-6

7782-77-6

Name	NITROUS ACID
CAS	7782-77-6
EINECS(EC#)	231-963-7
Molecular Formula	HNO2
MDL Number	MFCD01310438
Molecular Weight	47.01
MOL File	7782-77-6.mol

Chemical Properties

Appearance	A weak acid occurring only in the form of a light-blue solution.
density	1.54±0.1 g/cm3(Predicted)
form	stable only in solution
pka	pK (25°) 3.35
color	stable only in solution
PH	3.28(1 mM solution);2.67(10 mM solution);2.13(100 mM solution)
Uses	Formation of diazotizing compounds by reaction with primary aromatic amines, source of nitric oxide. less more
EPA Substance Registry System	Nitrous acid (7782-77-6)

Safety Data

Safety Profile

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.

Hazardous Substances Data

7782-77-6(Hazardous Substances Data)

Raw materials And Preparation Products

Hazard Information

Description

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”.

Physical properties

Pale blue solution; stable only in solution; weak acid, Ka 4.5x10^-4.

Definition

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.

Definition

nitrous acid: A weak acid, HNO₂,known only in solution and in thegas phase.It is prepared by the actionof acids upon nitrites, preferablyusing a combination that removesthe salt as an insoluble precipitate(e.g.Ba(NO₂)₂ and H₂SO₄). The solutionsare unstable and decompose on heating to give nitric acid and nitrogenmonoxide.Nitrous acid can functionboth as an oxidizing agent(forms NO) with I– and Fe2+, or as areducing agent (forms NO₃^-) with,forexample, Cu²⁺; the latter is mostcommon.It is widely used (preparedin situ) for the preparation of diazoniumcompounds in organic chemistry.The full systematic name isdioxonitric(III) acid.

Preparation

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.

Hazard

Rapidly forms nitric oxide and nitric acid in water; [Merck Index] A strong oxidizer; Causes burns; Highly toxic by ingestion and inhalation.

Questions And Answer

Supplier

Jiangsu Aikon Biopharmaceutical R&D co.,Ltd.

Telephone025-66113011 18112977050

Websitehttp://www.aikonchem.com

Lynnchem

Telephone86-(0)29-85992781 17792393971

Websitehttp://www.lynnchem.com/

Lianyungang Xuanyuan Chemical Co., Ltd

Telephone+86-0518-85415818 18000194506

Websitehttp://www.lygxychem.com

Rhawn Reagent

Telephone400-400-1332688 18019345275

Websitehttp://www.rhawn.cn

ShanDong Look Chemical Co.,Ltd.

Telephone +8617653113219

Websitehttps://www.sdlookchem.com/

Hubei yongkuo Technology Co., Ltd

Telephone027-59223108 15972152991

Websitehttps://www.chemicalbook.com/ShowSupplierProductsList1025246/0.htm

Hubei Shishun Biotechnology Co. Ltd

Telephone027-59223025 15107168801

Websitehttp://www.ss-bio.com/

Hebei Zhenjia new material Co., LTD

Telephone0319-5925599 13315915972

Websitehttp://china2699.com/

QUALITY CONTROL SOLUTIONS LTD.

Telephone0755-66853366 15920483169

Websitehttps://www.qcsrm.com

Shaanxi DIDU pharmaceutical and Chemical Co., Ltd

Telephone17691182729 18161915376

Websitehttp://www.dideu.cn

Hubei DAHAO Chemical Co., Ltd.

Telephone027-59106191 13986041085

Websitehttps://www.chemicalbook.com/ShowSupplierProductsList329222/0.htm

Qiyuan (Guangdong) Pharmaceutical Chemical Co., Ltd.

Telephone400-666-9280 18026564465

Websitehttps://www.chemicalbook.com/ShowSupplierProductsList1886377/0.htm

Golden Pharma Co., Limited

Telephone +undefined18958062155

Websitehttp://www.zjgoldpharm.com/

Hu Bei Jiutian Bio-medical Technology CO.,Ltd

Telephone027-88013699 17354350817

Websitewww.jiutian-bio.com

Shaanxi Didu New Materials Co. Ltd

Telephone+86-89586680 +86-13289823923

Websitehttps://www.dideu.com/en/

1of3

Related Products

Send Inquriy

7782-77-6

Chemical Properties

Safety Data

Raw materials And Preparation Products

Preparation Products

Hazard Information

Description

Physical properties

Definition

Definition

Preparation

Hazard

Questions And Answer

Chemical Properties

Uses

Reactions

Supplier

Related Products