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《研究萘的熔解过程》这个学生实验做完后,在试管壁上残留着少量的萘,要除去它是很麻烦的事。下面介绍一种除去试管壁上残留萘的方法,非常简单。 先将试管中的固态萘对准酒精灯的外焰加热,旋转试管。使试管均匀受热。稍时,管内的萘开始熔化。待到萘与试管不再粘结时,迅速将试管中的萘倒出,这时试管壁上只留一薄层萘粉。让试管自然冷却,再将冷却后的试管投入浓硝酸与浓盐酸按体积比约3:2的混
After the student’s experiment was done to study the melting process of naphthalene, a small amount of naphthalene remained on the wall of the tube, and it was troublesome to remove it. The following describes a method of removing residual naphthalene from a test tube wall. It is very simple. First heat the solid naphthalene in the test tube to the outer flame of the alcohol lamp and rotate the test tube. Allow the tube to heat evenly. At a moment, the naphthalene in the tube began to melt. When naphthalene and the test tube are no longer bonded, the naphthalene in the test tube is rapidly poured out, leaving only a thin layer of naphthalene powder on the wall of the test tube. Allow the tube to cool naturally, and then put the cooled tube into a mixture of concentrated nitric acid and concentrated hydrochloric acid in a volume ratio of about 3:2.