557. Ammonium Sulfite

Nomenclature

CAS number: 10196-04-0
Sulfurous acid ammonium salt (1:2).
H8N2O3S; mol wt 116.14.
H 6.94%, N 24.12%, O 41.33%, S 27.61%.
(NH4)2SO3.

Description and references

Prepn: Gmelins, Ammonium (8th ed.) 23, pp 256-258 (1936).

Derivative

Monohydrate.

Nomenclature

CAS number: 7783-11-1
H8N2O3S.H2O; mol wt 134.16.
H 7.51%, N 20.88%, O 47.70%, S 23.90%.

Properties

Efflorescent crystals. Under the influence of air and heat loses all its water of crystallization and is gradually oxidized to (NH4)2SO4. Sol in water; almost insol in alcohol, acetone. Its aq soln is alkaline to litmus. Keep tightly closed and in a cool place.

Use

In photography; as reducing agent; in bricks for blast-furnace linings; in lubricants for metal cold-working.