4236. Formaldehyde Sodium Bisulfite

Nomenclature

CAS number: 870-72-4
Hydroxymethanesulfonic acid monosodium salt; sodium formaldehydebisulfite; methylolsulfonic acid sodium salt.
CH3NaO4S; mol wt 134.09.
C 8.96%, H 2.26%, Na 17.15%, O 47.73%, S 23.91%.
HOCH2SO3Na.

Description and references

Prepn: Skrabal, Skrabal, Monatsh. Chem. 69, 17 (1936); Chhabria et al., DE 1173059 (1964 to Schill & Seilacher). Structure: Lauer, Langkammerer, J. Am. Chem. Soc. 57, 2360 (1935); Caughlan, Tartar, ibid. 63, 1266 (1941).

Derivative

Monohydrate.

Properties

Needles from water. pK (25°): 6.92.

Use

Fixing agent for keratin-containing fibers. Flotation of lead-zinc ores. Protecting color pictures exposed to high humidities against fading and staining.