Sulfur dioxide solution , AR,SO2≥6% , 7782-99-2
Synonym(s):
Sulfurous acid;Sulfurous anhydride
CAS NO.：7782-99-2
Empirical Formula: H2O3S
Molecular Weight: 82.08
MDL number: MFCD00011335
EINECS: 231-973-1
PRODUCT Properties
| Density | 1.03 g/mL at 25 °C(lit.) |
| vapor density | 2.3 (vs air) |
| solubility | solution of SO2 in H2O |
| pka | 1.92(at 25℃) |
| form | Liquid |
| color | Colorless |
| PH | pKa1= 1.658, pKa2 = 6.820(25℃) |
| Water Solubility | Miscible with water. |
| Sensitive | Air Sensitive |
| Merck | 14,8976 |
| Dielectric constant | 15.6（0℃） |
| Stability: | Stable. Incompatible with strong bases. |
| InChIKey | LSNNMFCWUKXFEE-UHFFFAOYSA-N |
| LogP | -1.579 (est) |
| CAS DataBase Reference | 7782-99-2(CAS DataBase Reference) |
| EPA Substance Registry System | Sulfurous acid (7782-99-2) |
Description and Uses
Sulfurous Acid is a weak and unstable inorganic acid, which is considered an aqueous solution of sulfur dioxide in water. It is formed theoretically by burning sulfur to produce sulfur dioxide, which is then reacted with water. However, there is no evidence that sulfurous acid exists in solution, while the molecules of which has been detected in the gas phase, since the reaction is reversible and the acid readily decomposes back into the reactants. Sulfurous acid is not usually available in its acid form, but more commonly prepared as its sodium or potassium salts.
Sulfurous acid and its salts are commonly applied as powerful reducing agents and disinfectant agents due to its strong reducibility. It is also considered as a mild bleaching agent especially for applications having chlorine sensitive materials. Besides, Sulfurous acid is a food additive listed on the EAFUS food Additive Database (Jan. 2001).
Sulfurous acid (H2SO3) can be produced by burning sulfur to form sulfur dioxide (SO2) gas and by then dissolving the gas in water to form sulfurous acid. This is the acid produced by burning coal that has a high sulfur content; the gaseous sulfur dioxide by-product of combustion then combines with atmospheric water to form “acid rain.”
Safety
| Symbol(GHS) |   GHS05,GHS07 |
| Signal word | Danger |
| Hazard statements | H314-H332 |
| Precautionary statements | P261-P271-P280-P303+P361+P353-P304+P340+P310-P305+P351+P338 |
| Hazard Codes | C,Xn |
| Risk Statements | 20-34-36/38 |
| Safety Statements | 26-36/37/39-45 |
| RIDADR | UN 1833 8/PG 2 |
| WGK Germany | 1 |
| RTECS | WT2775000 |
| F | 10-23 |
| TSCA | Yes |
| HazardClass | 8 |
| PackingGroup | II |
| HS Code | 28111990 |
