论文部分内容阅读
检验钠与水反应后,水溶液的性质时,一般是往溶液中滴酚酞试液,溶液立即变红说明生成了碱性物质氢氧化钠。那么做钠与水反应的演示实验中到底何时加入酚酞好,加入酚酞后溶液是否一定会变红?按照高级中学课本第一册94页对实验作的规定“向一个盛有水的烧杯中滴入几滴酚酞溶液”去做,这样有利于学生直观而清楚地了解酚酞溶液不能使水变颜色,当“把一小块钠投入盛有水的烧杯里”钠与水起反应后溶液的颜色立即发生变
After the reaction between sodium and water, the nature of the aqueous solution is tested, the phenolphthalein test solution is generally dropped into the solution, and the solution turns red immediately to indicate that an alkaline substance sodium hydroxide is generated. So when did you add phenolphthalein in the demonstration experiment of sodium and water reaction? After adding phenolphthalein, will the solution turn red? In accordance with the regulations for the experiment on page 94 of Book 1 of the High School Textbook, “To a beaker filled with water Dropping a few drops of phenolphthalein solution “doing this helps students intuitively and clearly understand that the phenolphthalein solution cannot make the water color, when ”put a small piece of sodium in a beaker filled with water" and sodium reacts with water. The color changes immediately