Hydroxylammonium sulfate

Hydroxylammonium sulfate
Names
Other names
Hydroxylamine sulfate
Identifiers
10039-54-0 Yes
ChemSpider 23229 Yes
EC number 233-118-8
Jmol-3D images Image
RTECS number NC5425000
UN number 2865
Properties
H8N2O6S
Molar mass 164.14 g/mol
Appearance white crystalline to fine product, slightly hygroscopic
Density 1.88 g/cm3
Melting point 120 °C (248 °F; 393 K) arose imposes around
58.7 g/100 ml (20 °C)
Hazards
MSDS External MSDS
EU Index 612-123-00-2
EU classification Explosive (E)
Carc. Cat. 3
Toxic (T)
Harmful (Xn)
Irritant (Xi)
Dangerous for the environment (N)
R-phrases R2, R21/22, R36/38, R40, R43, R48/22, R50
S-phrases (S2), S36/37, S61
NFPA 704
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g., canola oil Health code 3: Short exposure could cause serious temporary or residual injury. E.g., chlorine gas Reactivity code 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g., phosphorus Special hazards (white): no codeNFPA 704 four-colored diamond
1
3
2
Related compounds
Other anions
Hydroxylammonium nitrate
Hydroxylammonium chloride
Other cations
Ammonium sulfate
Hydrazinium sulfate
Related compounds
Hydroxylamine
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Hydroxylammonium sulfate, (NH3OH)2SO4, is the sulfuric acid salt of hydroxylamine. It is primarily used as an easily handled form of hydroxylamine, which is explosive when pure.

Synthesis

Hydroxylammonium sulfate can be obtained by the acid-base reaction of hydroxylamine with sulfuric acid:

2NH2OH(aq) + H2SO4(aq) → (NH3OH)2SO4(aq)

Applications

Hydroxylammonium sulfate is used in organic synthesis to convert aldehydes and ketones to oximes, carboxylic acids and their derivatives (e.g. esters) to hydroxamic acids, isocyanates to N-hydroxyureas and nitriles to amidoximes. Hydroxylammonium sulfate is also used to generate hydroxylamine-O-sulfonic acid from oleum or chlorosulfuric acid.

Hydroxylammonium sulfate is used in the production of anti-skinning agents, pharmaceuticals, rubber, textiles, plastics and detergents. It is a radical scavenger that terminates radical polymerization reactions and serves as an antioxidant in natural rubber. (NH3OH)2SO4 is a starting material for some insecticides, herbicides and growth regulators. It is used in photography as a stabiliser for colour developers and as an additive in photographic emulsions in colour film.

Decomposition

At 120 °C, hydroxylammonium sulfate begins to decompose to sulfur trioxide, nitrous oxide, water, and ammonia:

2(NH3OH)2SO4 → 2SO3 + N2O + 2NH3 + 5H2O

The reaction is exothermic above 138 °C, and is most exothermic at 177 °C.[1] Metals (especially copper, its alloys and its salts) catalyse the decomposition of hydroxylammonium sulfate. The instability of this compound is mainly due to the hydroxylammonium ion's weak nitrogen to oxygen single bond.

References

  1. BASF hydroxylammonium sulfate product page

External links