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中师化学第二册第132页的演示实验11—2中是这样说明的:在试管中加入少量苯酚晶体及水,振荡试管,试管中会出现浑浊液;再逐滴加入5％的氢氧化钠溶液,振荡试管,溶液变澄清、透明。而在实际操作中,振荡试管,苯酚晶体减少但不能完全消失,而溶液始终是澄清的,并不出现混浊现象。加入氢氧化钠溶液再振荡,苯酚晶体消失,溶液仍为澄清的。这样,苯酚与氢氧化钠的反应现象并不明显。笔者在几年的教学实践中,改用以下方法,效果较好。
The demonstration experiment 11-2 in the second division of the Chemistry Division of the Chemistry Division describes the following: In the test tube, add a small amount of phenol crystals and water, vortex the tube, and the turbid liquid will appear in the test tube; add dropwise 5% of the hydroxide The sodium solution shakes the test tube and the solution becomes clear and transparent. In practice, the oscillating tube reduces the phenol crystal but does not completely disappear, and the solution is always clear and does not appear cloudy. After adding sodium hydroxide solution and shaking, the phenol crystal disappears and the solution is still clear. In this way, the reaction between phenol and sodium hydroxide is not obvious. In the teaching practice of the author for several years, the following methods were adopted and the results were better.