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铝的特性是高二化学第六章第二节镁和铝的性质一节教学中的重点之一,又是教材中的难点。课本里只有一句话“……铝能跟强碱溶液反应,生成氢气和偏铝酸盐。”2Al+2NaOH+2H_2O=2NaAlO_2+3H_2↑在这个反应里,铝置换了氢氧化钠中的氢还是水中的氢?氢氧化钠和水哪个是氧化剂?为了解决教材中这个突出的问题,我们设计作了以下几个小实验: 1.把铝片放在盛有水的烧杯中观察无气泡产生; 2.将铝片取出放在盛有NaOH溶液(30%)的烧杯中观察有大量气泡产生;
The characteristics of aluminum are one of the key points in the teaching of the nature of magnesium and aluminum in the second section of the second chapter of Gao II Chemistry, and it is also a difficult point in the textbook. There is only one sentence in the textbook...“Aluminium reacts with a strong alkali solution to produce hydrogen and metaaluminates.”“2Al+2NaOH+2H2O=2NaAlO2+2+3H2” In this reaction, aluminum replaces the sodium hydroxide. Hydrogen or hydrogen in water? Which is an oxidizing agent for sodium hydroxide and water? In order to solve this outstanding problem in the textbook, we designed the following small experiments: 1. Put the aluminum plate in a beaker filled with water to observe no bubbles Generated; 2. The aluminum film was removed and placed in a beaker containing NaOH solution (30%) to observe a large number of bubbles generated;