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高中化学课本上,在介绍电解食盐水以制取烧碱和氯气时,电极反应式是这样表述的:阴极、2H~++2e=2H 2H=H_2 阳极:2Cl~--2e=2Cl 2Cl=Cl_2 我认为上述阴极的电极反应式未能将阴极反应的实质表现出来。因为在阴极放电的 H~+是由水电离产生的,而水是弱电解质,写离子方程式时仍应保持分子形式。因此,电解食盐水时,正确的阴极的电极反应表达式应该是:(阳极电极反应式同上。)
In high school chemistry textbooks, when introducing electrolytic brine to produce caustic soda and chlorine, the electrode reaction formula is expressed as follows: Cathode, 2H~++2e=2H 2H=H_2 Anode: 2Cl~--2e=2Cl 2 Cl=Cl_2 I think that the above cathode electrode reaction fails to show the nature of the cathode reaction. Since the H~+ at the cathode discharge is generated by the ionization of water, and water is a weak electrolyte, the molecular form should still be maintained when the ion equation is written. Therefore, when electrolyzing salt water, the correct cathode electrode reaction expression should be: (The anode electrode reaction is the same as above.)