论文部分内容阅读
现行高中必修课本第一册第69页倒数第一行有如下的叙述:“由此可见,用可溶性钡盐溶液和盐酸(或稀硝酸)可以检验硫酸根离子(SO_4~(2-))的存在。” 笔者认为此种提法不严密。因为教材仅是从有限的不溶于水的钡盐(如碳酸钡、磷酸钡)能溶于盐酸或稀硝酸而得出上述结论的。既没有考虑含有Ag~+(或Hg_2~(2+)、pb~(2+))而不含SO_4~(2-)的无色透明溶液,也没有考虑含有SO_3~(2-)而不含SO_4~(2-)的无色透明溶液。此两种情况下都可能出现与含SO_4~(2-)的无色透明溶液相同的现
The penultimate line of the first penultimate line of the current High School Compulsory Textbook Volume 1 is as follows: “It can be seen that the soluble sulfate solution and hydrochloric acid (or dilute nitric acid) can be used to test the sulfate ion (SO_4~(2-)) Exist." The author believes that this reference is not strict. This is because the teaching materials only come from the limited water-insoluble barium salts (such as barium carbonate and barium phosphate) that are soluble in hydrochloric acid or dilute nitric acid. We did not consider the colorless and transparent solution containing Ag~+ (or Hg_2~(2+), pb~(2+)) and SO_4~(2-) and did not consider SO_3~(2-) A colorless, transparent solution containing SO_4~(2-). In both cases, the same colorless and transparent solution containing SO_4~(2-) may appear.