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一、知识点回顾1.钠与水反应实验操作要点(1)所取反应的钠的体积不能过大,绿豆大小即可.(2)用滤纸吸干表面的煤油,注意手不要接触到金属钠.(3)用镊子把上述绿豆大小的钠放在滴有几滴酚酞的水中,若以烧杯作反应器,注意烧杯中的水不能过多,以防止钠与水反应时钠块或液体飞溅伤人,可`在烧杯口盖上玻璃片.2.钠放入滴有几滴酚酞的水中的实验现象(1)浮:钠浮在水面上,说明钠的密度比水
First, the knowledge point of review 1. Sodium and water reaction experimental points (1) the size of the reaction to take sodium can not be too large, mung bean size can be. (2) filter paper surface kerosene, pay attention to hands do not come into contact with the metal Sodium. (3) Using tweezers to place the above-mentioned mung bean-sized sodium in drops of phenolphthalein water, if a beaker is used as a reactor, note that the water in the beaker should not be excessive to prevent sodium or water from reacting with the sodium Splash wound, can `glass on the lid of the beaker .2 sodium drop into a few drops of phenolphthalein water experimental phenomenon (1) floating: sodium floating on the water, indicating that the density of sodium than water