ISO 3196:1975 工业用氢氧化钠.碳酸盐含量的测定.滴定法

标准编号：ISO 3196:1975

中文名称：工业用氢氧化钠.碳酸盐含量的测定.滴定法

英文名称：Sodium hydroxide for industrial use — Determination of carbonates content — Titrimetric method

发布日期：1975-05

标准范围

适用于二氧化碳含量超过0.01%（m/m）的产品。涉及既不含硫化物也不含氯酸盐或仅含硫化物或仅含氯酸盐的产品。通过在甲基橙存在下煮沸酸化试样并在蒸汽中使用醋酸铅纸条进行初步试验。硫化物使纸张变黑，氯酸盐使甲基橙脱色。既不含硫化物也不含氯酸盐的产品:通过酸化和加热释放二氧化碳。气流夹带和过量氢氧化钡溶液吸收。以百里酚酞为指示剂，用标准体积盐酸溶液滴定过量的氢氧化钡溶液。

Applicable to products having contents, expressed as CO2, of more than 0.01 % (m/m). Relates to a procduct containing neither sulphides nor chlorates or only sulphides or only chlorates. Preliminary test by boiling an acidified test sample in the presence of methyl orange and with a lead acetate paper strip in the vapour. The sulphides blacken the paper and chlorates delolourize the methyl orange. Products containing neither sulphides nor chlorates: liberation of carbon dioxide by acidification and heating. Entrainment in a flow of gas and absorption in an excess of barium hydroxide solution. Titration of the excess barium hydroxide solution with a standard volumetric hydrochloric acid solution in the presence of thymolphthalein as indicator.

标准预览图