SO42－的鉴定有它的一般规律性和特殊性。一般规律检验某化合物中是否含有SO42－时，取纯净物溶于水制成溶液，再取溶液少许于试管中，滴加氯化钡溶液，产生白色沉淀，再加稀硝酸，白色沉淀不消失，由此可一般性的确定原化合物中含有SO42－（其中的白色沉淀为BaSO4）。特例当溶 The identification of SO42- has its general regularity and particularity. When the general rule is to check whether a certain compound contains SO42-, take a solution of pure substance dissolved in water and take a little solution in a test tube. Add a solution of cesium chloride to produce a white precipitate, and then add dilute nitric acid to remove the white precipitate. Therefore, it can be generally determined that the original compound contains SO42- (in which the white precipitate is BaSO4). Special case when dissolved