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氢氧化锂中二氧化碳的侧定,一般采用酸碱滴定法进行,即以酚酞及甲基橙作指示剂,用盐酸溶液连续滴定OH~-、CO_3~=及HCO_3~-,或用盐酸溶液分别滴定总碱度及用氯化钡沉淀碳酸盐后滴定OH~-来计算二氧化碳含量。酸碱滴定法手续简单、快速。但是由于氢氧化锂中氢氧根的大量存在,碳酸根量又此较少,因此两次滴定过程中对碳酸根所引起的相对差也就较大,终点变化也不太明显。另一方面由于氢氧化锂试样对空气中二氧化碳的吸收较快,在操作过程中又很难避免试样与空气接触。因此由于环境空气中二氧碳浓度的不同,以及操作人员熟练程度的不同,就会使结果产生较大的偏差。为了提高氢氧化锂中测定二氧化碳的准确度,我们对蒸馏一氢氧化钡吸收测定二氧化碳的方法进行了一些改进,设计制作了一套简单
Lithium hydroxide, carbon dioxide in the side, the general use of acid-base titration method, that phenolphthalein and methyl orange as an indicator, with hydrochloric acid solution continuous titration OH ~ -, CO_3 ~ = and HCO_3 ~ -, or with hydrochloric acid solution Titrate total alkalinity and titrate OH ~ - with carbonate precipitated with barium chloride to calculate the carbon dioxide content. Acid-base titration method is simple and fast. However, because of the presence of a large amount of hydroxide in lithium hydroxide, the amount of carbonate is less, so the relative difference caused by carbonate during the two titration processes is also larger, and the end point change is not obvious. On the other hand, because lithium hydroxide sample absorbs carbon dioxide in the air quickly, it is very difficult to avoid the contact of the sample with the air during the operation. Therefore, due to different concentrations of dioxygen in the ambient air, as well as the different proficiency of operators, the result will be greatly deviated. In order to improve the accuracy of determination of carbon dioxide in lithium hydroxide, we carried out some improvements on the method of absorbing and determining carbon dioxide by distillation of barium hydroxide. We designed and made a simple