Liquid Sulphur Dioxide So2

Sulfur dioxide

Sulfur dioxide,liquid;sulfurous acid gas;Sulfur dioxide;Sulfur dioxide Standard;siarkidwutlenek(polish);Sulfur oxide;Sulfur oxide (SO2);sulfur dioxide pressure tin with 100 ml (net ~128 G)

7446-09-5

O2S

RAHZWNYVWXNFOC-UHFFFAOYSA-N

64.06

64.06

3535237

231-195-2

TSCA listed

colorless

2811290090

Oxides and Peroxides

66.23000

Colorless gas; pungent suffocating odor; gas density 2.927 g/L at 20°C; heavier than air, vapor density 2.263 (air=1); condenses to a colorless liquid at -10°C; density of liquid SO21.434 g/mL; freezes at -72.7°C; critical temperature 157.65°C; critical pressure 77.78 atm; critical volume 122 cc/g; dielectric constant 17.27 at -16.5°C; dissolves in water forming sulfurous acid, solubility 22.97 g and 11.58 g/100mL water at 0° and 20°C, respectively, under atmospheric pressure; very soluble in acetone, methyl isobutyl ketone, acetic acid, and alcohol; soluble in sulfuric acid; liquid SO2slightly miscible in water.

0.41060

Sulfur dioxide appears as a colorless gas with a choking or suffocating odor. Boiling point -10°C. Heavier than air. Very toxic by inhalation and may irritate the eyes and mucous membranes. Under prolonged exposure to fire or heat the containers may rupture violently and rocket. Used to manufacture chemicals, in paper pulping, in metal and food processing. Rate of onset: Immediate & Delayed Persistence: Minutes to hours Odor threshold: 1 ppm Source/use/other hazard: Disinfectant and preserving in breweries and food/canning; textile industry; batteries.

1.25 g/mL at 25 °C (lit.)

-73 °C (lit.)

-10 °C (lit.)

1.510

%H2O: 17.7 (0°C), 11.9 (15°C), 8.5 (25°C), 6.4 (35°C); % other solvents: 25, alcohol; 32, methanol [MER06]

Sulfur dioxide is noncorrosive and stable when dry. It is usually stored under pressure in cylinders, and should be kept in a cool, dry, well-ventilated area, away from flammable materials.

1779 mm Hg ( 21 °C)

2.26 (21 °C, vs air)

Conversion of sulfur dioxide to bisulfite in the airway may initiate bronchoconstriction, due to the ability of the more reactive bisulfite ion to disrupt disulfide bonds in tissue proteins, resulting in tissue damage and an inflammatory response. Sulfites and bisulfites can further inhibit DNA synthesis and cause human lymphocyte aberrations and can lead to crosslinking in proteins and nucleic acids in general, as well as generate free radicals during their oxidation to sulfates.Bronchoconstriction and other related effects may be mediated by release of leukotrienes, prostaglandins, or other inflammatory factors. Some evidence suggests that free radicals and oxidative stress may play a role, and that metabolites of SO2 (especially sulfites) may be responsible for clastogenicity. Sulfur dioxide–induced bronchoconstriction, occurs when the gas acts on tracheobronchial receptors to induce a cholinergic reflex. Inhaled sulfur dioxide elicited a stronger reaction in sulfite oxidase–deficient rats than endogenously accumulated sulfites and S-sulfocysteine (a reaction product of sulfite with cysteine residues in proteins). Noncholinergic mechanisms for sulfur dioxide–induced bronchoconstriction have been demonstrated in humans as well. In one study, asthmatic subjects were administered indomethacin – a prostaglandin synthetase inhibitor – followed by challenge with sulfur dioxide gas; a reduction in airway responsiveness was observed.

Sulfur dioxide is a noncombustible substance (NFPA rating = 0).

An explosive when compressed.

Pungent odor detectable at 0.3 to 5 ppm

Acid taste

1.3×10-2mol/(m3Pa) at 25℃, Burkholder et al. (2019)

Dissolves in water to form sulfurous acid, a corrosive liquid. Moist Sulfur dioxide is very corrosive due to the slow formation of sulfuric acid [Handling Chemicals Safely 1980 p. 876].

Sulfur dioxide is acidic. Reacts exothermically with bases such as amines, amides, metal oxides, and hydroxides. Frequently used as a reducing agent although Sulfur dioxide is not a powerful one. Acts as a reducing bleach to decolorize many materials. Can act as an oxidizing agent. Supports combustion of powdered aluminum [Mellor 5:209-212 1946-47]. Reacts explosively with fluorine [Mellor 2:1 1946-47]. Supports burning of manganese [Mellor 12:187 1946-47]. Readily liquefied by compression. Contact between the liquid and water may result in vigorous or violent boiling and extremely rapid vaporization. If the water is hot an explosion may occur. Pressures may build to dangerous levels if the liquid contacts water in a closed container [Handling Chemicals Safely 1980]. Supports incandescent combustion of monocesium acetylide, monopotassium acetylide, cesium oxide, iron(II) oxide, tin oxide, and lead oxide [Mellor]. Ethylene oxide and SO2 can react violently in pyridine solution with pressurization if ethylene oxide is in excess (Nolan, 1983, Case History 51).