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氢氧化钠溶液能使无色酚酞溶液变红,但在实际的实验中,常常会遇到无色酚酞溶液变红后,很快颜色又褪去,现通过实验从无色酚酞溶液是否变质、无色酚酞溶液的浓度、无色酚酞溶液的用量及氢氧化钠溶液的浓度等因素来探究无色酚酞溶液变红后褪色的原因.一、问题的提出无色酚酞溶液作为中学化学中一种常用的酸碱指示剂,在化学学习中具有重要的作用,利用无色酚酞溶液可以简单的判断物质的酸碱性.在人教版九年级化学下册第十单元课题2“酸
Sodium hydroxide solution can make colorless phenolphthalein solution turns red, but in actual experiments, often encounter the colorless phenolphthalein solution turns red, soon color and fade, now through experiments from colorless phenolphthalein solution is metamorphic, no Color phenolphthalein solution concentration, the amount of colorless phenolphthalein solution and sodium hydroxide solution concentration and other factors to explore the colorless phenolphthalein solution reddish fading after the reason.First, the problem of colorless phenolphthalein solution as a middle school chemistry Acid-base indicator, has an important role in chemical learning, the use of colorless phenolphthalein solution can easily determine the material’s acid-base. In the People’s Education Edition ninth grade chemistry under the tenth unit topic 2 ”acid