<Table> Sulfur dioxide <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Th_colspan="2"> Names </Th> </Tr> <Tr> <Td_colspan="2"> IUPAC name Sulfur dioxide </Td> </Tr> <Tr> <Td_colspan="2"> Other names Sulfurous anhydride Sulfur (IV) oxide </Td> </Tr> <Tr> <Th_colspan="2"> Identifiers </Th> </Tr> <Tr> <Td> CAS Number </Td> <Td> <Ul> <Li> 7446 - 09 - 5 </Li> </Ul> </Td> </Tr> <Tr> <Td> 3D model (JSmol) </Td> <Td> <Ul> <Li> Interactive image </Li> </Ul> </Td> </Tr> <Tr> <Td> Beilstein Reference </Td> <Td> 3535237 </Td> </Tr> <Tr> <Td> ChEBI </Td> <Td> <Ul> <Li> CHEBI: 18422 </Li> </Ul> </Td> </Tr> <Tr> <Td> ChEMBL </Td> <Td> <Ul> <Li> ChEMBL1235997 </Li> </Ul> </Td> </Tr> <Tr> <Td> ChemSpider </Td> <Td> <Ul> <Li> 1087 </Li> </Ul> </Td> </Tr> <Tr> <Td> ECHA InfoCard </Td> <Td> 100.028. 359 </Td> </Tr> <Tr> <Td> EC Number </Td> <Td> 231 - 195 - 2 </Td> </Tr> <Tr> <Td> E number </Td> <Td> E220 (preservatives) </Td> </Tr> <Tr> <Td> Gmelin Reference </Td> <Td> 1443 </Td> </Tr> <Tr> <Td> KEGG </Td> <Td> <Ul> <Li> D05961 </Li> </Ul> </Td> </Tr> <Tr> <Td> MeSH </Td> <Td> Sulfur + dioxide </Td> </Tr> <Tr> <Td> PubChem CID </Td> <Td> <Ul> <Li> 1119 </Li> </Ul> </Td> </Tr> <Tr> <Td> RTECS number </Td> <Td> WS4550000 </Td> </Tr> <Tr> <Td> UNII </Td> <Td> <Ul> <Li> 0UZA3422Q4 </Li> </Ul> </Td> </Tr> <Tr> <Td> UN number </Td> <Td> 1079, 2037 </Td> </Tr> <Tr> <Td_colspan="2"> InChI (show) <Ul> <Li> InChI = 1S / O2S / c1 - 3 - 2 Key: RAHZWNYVWXNFOC - UHFFFAOYSA - N </Li> <Li> InChI = 1 / O2S / c1 - 3 - 2 Key: RAHZWNYVWXNFOC - UHFFFAOYAT </Li> </Ul> </Td> </Tr> <Tr> <Td_colspan="2"> SMILES (show) <Ul> <Li> O = S =O </Li> </Ul> </Td> </Tr> <Tr> <Th_colspan="2"> Properties </Th> </Tr> <Tr> <Td> Chemical formula </Td> <Td> SO </Td> </Tr> <Tr> <Td> Molar mass </Td> <Td> 64.066 g mol </Td> </Tr> <Tr> <Td> Appearance </Td> <Td> Colorless gas </Td> </Tr> <Tr> <Td> Odor </Td> <Td> Pungent; similar to a just - struck match </Td> </Tr> <Tr> <Td> Density </Td> <Td> 2.6288 kg m </Td> </Tr> <Tr> <Td> Melting point </Td> <Td> − 72 ° C; − 98 ° F; 201 K </Td> </Tr> <Tr> <Td> Boiling point </Td> <Td> − 10 ° C (14 ° F; 263 K) </Td> </Tr> <Tr> <Td> Solubility in water </Td> <Td> 94 g / L forms sulfurous acid </Td> </Tr> <Tr> <Td> Vapor pressure </Td> <Td> 237.2 kPa </Td> </Tr> <Tr> <Td> Acidity (pK) </Td> <Td> 1.81 </Td> </Tr> <Tr> <Td> Basicity (pK) </Td> <Td> 12.19 </Td> </Tr> <Tr> <Td> Magnetic susceptibility (χ) </Td> <Td> − 18.2 10 cm / mol </Td> </Tr> <Tr> <Td> Viscosity </Td> <Td> 0.403 cP (at 0 ° C) </Td> </Tr> <Tr> <Th_colspan="2"> Structure </Th> </Tr> <Tr> <Td> Point group </Td> <Td> </Td> </Tr> <Tr> <Td> Coordination geometry </Td> <Td> Digonal </Td> </Tr> <Tr> <Td> Molecular shape </Td> <Td> Dihedral </Td> </Tr> <Tr> <Td> Dipole moment </Td> <Td> 1.62 D </Td> </Tr> <Tr> <Th_colspan="2"> Thermochemistry </Th> </Tr> <Tr> <Td> Std molar entropy (S) </Td> <Td> 248.223 JK mol </Td> </Tr> <Tr> <Td> Std enthalpy of formation (Δ H) </Td> <Td> − 296.81 kJ mol </Td> </Tr> <Tr> <Th_colspan="2"> Hazards </Th> </Tr> <Tr> <Td> EU classification (DSD) (outdated) </Td> <Td> </Td> </Tr> <Tr> <Td> R - phrases (outdated) </Td> <Td> R23, R34, R50 </Td> </Tr> <Tr> <Td> S - phrases (outdated) </Td> <Td> (S1 / 2), S9, S26, S36 / 37 / 39, S45 </Td> </Tr> <Tr> <Td> NFPA 704 </Td> <Td> 0 0 </Td> </Tr> <Tr> <Td_colspan="2"> Lethal dose or concentration (LD, LC): </Td> </Tr> <Tr> <Td> LC (median concentration) </Td> <Td> 3000 ppm (mouse, 30 min) 2520 ppm (rat, 1 hr) </Td> </Tr> <Tr> <Td> LC (lowest published) </Td> <Td> 993 ppm (rat, 20 min) 611 ppm (rat, 5 hr) 764 ppm (mouse, 20 min) 1000 ppm (human, 10 min) 3000 ppm (human, 5 min) </Td> </Tr> <Tr> <Td_colspan="2"> US health exposure limits (NIOSH): </Td> </Tr> <Tr> <Td> PEL (Permissible) </Td> <Td> TWA 5 ppm (13 mg / m) </Td> </Tr> <Tr> <Td> REL (Recommended) </Td> <Td> TWA 2 ppm (5 mg / m) ST 5 ppm (13 mg / m) </Td> </Tr> <Tr> <Td> IDLH (Immediate danger) </Td> <Td> 100 ppm </Td> </Tr> <Tr> <Th_colspan="2"> Related compounds </Th> </Tr> <Tr> <Td> Related sulfur oxides </Td> <Td> Sulfur monoxide Sulfur trioxide </Td> </Tr> <Tr> <Td> Related compounds </Td> <Td> Ozone <P> Selenium dioxide Sulfurous acid Tellurium dioxide </P> </Td> </Tr> <Tr> <Td_colspan="2"> Except where otherwise noted, data are given for materials in their standard state (at 25 ° C (77 ° F), 100 kPa). </Td> </Tr> <Tr> <Td_colspan="2"> verify (what is?) </Td> </Tr> <Tr> <Td_colspan="2"> Infobox references </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> </Tr> </Table> <Tr> <Th_colspan="2"> Names </Th> </Tr> <Tr> <Td_colspan="2"> IUPAC name Sulfur dioxide </Td> </Tr>

How is the moisture present in so2 gas removed