Sulfur dioxide dissolved in water

Sulfur dioxide dissolves in water forming sulfurous acid that is stable only in solution ... 

Sulfur dioxide dissolves in water, forming a weak acid solution of sulfiirous acid, H2S03 however, the pure substance H2S03 has never been isolated. At 101.3 kPa (1 atm) sulfur dioxide pressure, the solubility of sulfur dioxide is 18.5% at 0°C and 5.1% at 40°C. Lower solubilities are observed when other diluent gases, eg, air, are present. At 25°C, the hypothetical H2S03 has a first ionization constant of 1.72 x 10-2 and a second ionization constant of 1.1 x 10-9. Atlow temperatures, concentrated sulfurous acid affords a crystalline hydrate, S02 6H20 [24402-69-5]. 

Sulfur dioxide dissolved in water forms an equilibrium mixture ... 

When sulfur dioxide dissolves in water, an acidic solution is formed. The gas is quite soluble (at 20 °C, 3940 cm3 of SO2 dissolves in 100 g of H20 at 1 atm), and the acidic solution is called sulfurous acid. Presumably, the reactions that take place can be written as follows ... 

Sheppard (1988) examined the chemical mechanisms that underlie the bronchoconstrictive effect of sulfur dioxide. Sulfur dioxide dissolves in water to form bisulfite ion, sulfite ion, and hydrogen ion. The bisulfite ion is a nucleophile that can disrupt disulfite bonds. It has been postulated that bisulfite... 

Sulfur dioxide dissolves in water to form an acidic solution. The reaction is often represented as... 

Sulfur dioxide dissolves in water droplets (fog, clouds, and rain) in the atmosphere and reacts according to the equation... 

Sulfurous acid (H2SO3), formed when sulfur dioxide dissolves in water, exists in equilibrium with hydrated SO2 rather than as stable H2SO3 molecules ... 

Sulfurous acid (H2S03) is a colorless liquid, prepared by dissolving sulfur dioxide (S02) in water. Reagent grade sulfurous acid contains approximately 6% sulfur dioxide in solution. 

Water enters the kernel mostly at the tip cap and moves quickly through voids in the pericarp by capillary action or through the germ into the endosperm, as discussed earlier in this chapter.24,26,27 137 Fan et al.138 showed that the effect of sulfur dioxide dissolved in the water is to increase the rate of water diffusion into dent com kernels. Increasing the temperature up to 60°C increases the rate of water diffusion. After 17 hours steep at 49°C, the moisture increase was 25% higher in the sulfur dioxide solution than in water... 

Substitution of potassium ferricyanide for 1% of sulfur dioxide dissolved in calcium-base spent sulfite liquor was possible at a pH of about 2.0. An increase in pH stabilized the cross-linking mixture unless 4% of ammonium chloride (dry wood basis) was added. In this case particle board could be produced at a pH of 4.5, with properties equivalent to those produced at a pH of 2.0, i.e., with IB values of up to 82.0 psi and acceptable water resistance (JOS, 109). 

This reaction shows that solid calcium carbonate reacts with a heated solution of sulfuric acid dissolved in water to form solid calcium sulfate, carbon dioxide gas, and liquid water. 

In (2), the heavier sulfonic acid-rich phase is separated from part of the residual hydrocarbon, which is recycled (13). The remaining paraffin is solubilized in sulfonic acid aggregates. In (3), the sulfur dioxide dissolved in the lower phase is expelled (10) by means of air (16). Water is then distilled off in vacuo (4), together with some paraffin, and on such concentration of the aqueous... 

Selenium trioxide, SeO, is white, crystalline, and hygroscopic. It can be prepared by the action of sulfur trioxide on potassium selenate or of phosphorous pentoxide on selenic acid. It forms selenic acid when dissolved in water. The pure trioxide is soluble in a number of organic solvents. A solution in Hquid sulfur dioxide is a selenonating agent. It is stable in very dry atmospheres at room temperature and on heating it decomposes first to selenium pentoxide [12293-89-9] and then to selenium dioxide. 

The oxidation catalyst (OC) operates according to the same principles described for a TWO catalyst except that the catalyst only oxides HC, CO, and H2. It does not reduce NO emissions because it operates in excess O2 environments. One concern regarding oxidation catalysts was the abiUty to oxidize sulfur dioxide to sulfur trioxide, because the latter then reacts with water to form a sulfuric acid mist which is emitted from the tailpipe. The SO2 emitted has the same ultimate fate in that SO2 is oxidized in the atmosphere to SO which then dissolves in water droplets as sulfuric acid. 

Sulfur oxides (SO,) are compounds of sulfur and oxygen molecules. Sulfur dioxide (SO2) is the predominant form found in the lower atmosphere. It is a colorless gas that can be detected by taste and smell in the range of 1, (X)0 to 3,000 uglm. At concentrations of 10,000 uglm , it has a pungent, unpleasant odor. Sulfur dioxide dissolves readily in water present in the atmosphere to form sulfurous acid (H SOj). About 30% of the sulfur dioxide in the atmosphere is converted to sulfate aerosol (acid aerosol), which is removed through wet or dry deposition processes. Sulfur trioxide (SO3), another oxide of sulfur, is either emitted directly into the atmosphere or produced from sulfur dioxide and is readily converted to sulfuric acid (H2SO4). 

Sulfur dioxide is extremely stable to heat, even up to 3600°F. It docs not form flammable or cxplosi c mixtures witli air. It will, howe cr, react with water or steam to produce toxic and corrosive fumes.When the gas dissolves in water it forms a weak acid solution of sulfurous acid (H S03), which is corrosi C [Pg.274]

In the meantime, a sodium sulfite solution is prepared by dissolving 890 g. of sodium hydroxide, of about 90 per cent purity, in about 1 1. of water and then diluting to 6 1. A few drops of phenolphthalein solution are added and sulfur dioxide passed in, first until an acid reaction is indicated and then for two or three minutes longer. During the addition of the sulfur dioxide, the solution is cooled with running water. On account of the strong alkaline solution, the original color produced by... 

Trickle bed gas absorber-reactor. Sulfur dioxide is to be removed from a gas by passing the gas and water through a bed of highly porous activated carbon kept at 25°C. In this system sulfur dioxide and oxygen dissolve in water and react on the solid to give sulfur trioxide, as follows ... 

In the third pathway, sulfur dioxide first dissolves in water and then is oxidized to sulfuric acid by a variety of reactions ... 

Sulfur dioxide gas dissolves in water to set up equilibria similar to those of C02 ... 

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