Specification of Sodium Hydrosulfite

CAS No.  

7775-14-6

EINECS No

231-890-0

Formula

Na2 O4 S2

Mol Wt.  

174.10

HS Code 

2831.10

Physical and Chemical Properties

Solubility In Water

Soluble (insoluble in alcohol)

pH  

Acidic in solution

Flash Point  

90 °C

Stability

Stable under ordinary conditions (Decomposes in  hot water and acid)

Na2 O4 S2 

85% or 88% or 90% min

Insolubles In Water

0.1% max 

Na2S2O3

1.2% max

Na2S2O5

5-7% 

NaHSO3

0.5% max

Na2CO3

0.6-2%

HCOONa   

0.5% max 

Zn   

0.0001% max

Pb

0.0001% max

Fe 

0.005% max