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|Section2= |Section3= |Section7= |Section8= }} Sodium sulfite (sodium sulphite) is a soluble sodium salt of sulfurous acid (sulfite) with the chemical formula Na2SO3. It is a product of sulfur dioxide scrubbing, a part of the flue-gas desulfurization process. It is also used as a preservative to prevent dried fruit from discoloring, and for preserving meats, and is used in the same way as sodium thiosulfate to convert elemental halogens to their respective hydrohalic acids, in photography and for reducing chlorine levels in pools. ==Preparation== Sodium sulfite can be prepared in lab by reacting sodium hydroxide solution with sulfur dioxide gas: :2 NaOH + SO2 → Na2SO3 + H2O Evolution of SO2 by adding few drops of concentrated hydrochloric acid will indicate if sodium hydroxide is nearly gone, turned to aqueous sodium sulfite: :Na2SO3 + 2 HCl → 2 NaCl + SO2 + H2O Sodium sulfite is made industrially by reacting sulfur dioxide with a solution of sodium carbonate. The initial combination generates sodium bisulfite (NaHSO3), which is converted to the sulfite by reaction with sodium hydroxide or sodium carbonate. The overall reaction is: :SO2 + Na2CO3 → Na2SO3 + CO2 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「sodium sulfite」の詳細全文を読む スポンサード リンク
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