Preperation and used of Hydroxyamine (NH2OH) and Hydroic acid. (N3H)

Preparation of Hydroxylamine.(NH₂OH).

It is unstable and they are decomposed into NH₃, N₂, HNO₂, and N₂O. Therefore, it is handled in aqueous solution or one of its salts (these salts are more stable than free NH₂OH).

Salts of NH₂OH:[NH₃OH]⁺, Cl^-, [NH₃OH]+,HSO₄^-,

Preparation.

$$NH_4NO_2+NH_4HSO_3+SO_2+2H_2O→[NH_3OH]^+Cl^-+(NH_4)_2SO_4$$

$$CH_3NO_2+H_2SO_4→[NH_3OH]^+HSO_4^-+CO$$

Uses of Hydroxyamine.

It is used as a reagent in organic chemistry for identification of carbonyl compound. NH₂OH is used in the manufacture of large panties to make ketoxime, which converted to caprolactam and then polymerised to nylon-6.

Properties.

1. NH₂OH is a weak base than NH₃ as the lone pair is not available the same extent as in NH₃.
2. It is very unstable and decomposed even at room tempertaure.

$$3NH_2OH+→N_2+NH_3+3H_2O$$

$$4NH_2OH+→2NH_3+N_2O+3H_2O$$

$$NH_2OH \,is\,mono\,basic\,acid.$$

$$NH_2OH+H_2O→[NH_3OH]^+OH^-$$

$$[NH_3OH]OH+HCl=[HONH_3]Cl+H_2O$$

It forms a series of coordinate compound through a lone pair present on nitrogen.

Reducing property.

$$4CuO+2NH_2OH\xrightarrow{Alkaline}2Cu_2O+3H_2O+N_2O$$

$$4AuCl_3+6NH_2OH\xrightarrow{Acidic}4Au+3N_2O+12HCl+3H_2O$$

$$4FeCl_3+2NH_2OH\xrightarrow{Acidic}4FeCl_2+N_2O+H_2O+4HCl$$

Oxidising property.

$$2Fe(OH)_2+NH_2OH+H_2O=NH_3+2Fe(OH)_3$$

$$22NH_2OH+H_2O_2=NH_3+H_2O+O_2$$

$$NH_2OH+HI=NH_3+I_2+H_2O$$

Structure of Hydroxyamine.

Preparation properties and structure of Hydrazoic acid.

Preparation

1. From hydrazine salts.

$$NH_2.NH_2.HCl+NaNO_2→NH_2NH_2HNO_2+NaCl$$

$$NH_2NH_2HNO_2→N_3H+2H_2O$$

2. By shaking nitrogen trichloride with hydrazine salts in benzene solution.

$$NH_2NH_2+NCl_3→N_3H+3HCl$$

Properties.

1. Free N3H is a colourless liquid b.p(37^oC), toxic, and explosive.

$$3N_3H→4N_2+NH_3$$

2. It is readily soluble in alcohol and in water.

3. Acid strength of NH₃ is similar to CH₃COOH.

4. It is stable in aqueous solution but unstable in pure form. Light can initiate the decomposition into nitrogen and ammonia.

5. Reacts with electropositive metal

$$6NH_3+4Li→LiN_3+2NH_3+2N_2$$

6. Salts of heavy metal known as azides are generally explosive; those of Pb, Hg, Ag and Ba explode if struck sharply.

7. $$Zn+3N_3H→Zn(N_3)_2+N_2+NH_3$$

$$2N_3H+Mg→(N_3)_2Mg+H_2$$

Oxidising agent.

When N₃H reacts with substance like arsenic or sodium amalgam it is reduced to N₂H₄ or NH₃.With finely divided Platinium it gives ammonia.

$$N_3H\xrightarrow{H_2\,Pt}NH_3$$

Reducing agent

N₃H can be oxidised by stronger oxidising agents.It can also be oxidised by HNO₂ and hypochlorous acid.

.1. with KMnO4.

$$2N_3H\xrightarrow{(O)}3N_2+H_2O$$

2. With HNO₂.

$$N_3H+OHNO→N_2+N_2OH_2O$$

Structure.

Reference.

F.A.Cotton and Wilkinson G. Basic inorganic Chemistry. John,Wiley and Sons (Asia), 2007.

Lee., J.D. Concise Inorganic Chemistry. fifth edition. New Delhi: Oxford University Press., 2008.

Sharma, M.L and P.N Chaudhary. A textbook of B.S.C chemistry. Kathmandu Nepal: Ekta Books Thapathali Kathmandu, 2011.