Precautions during tube heating

When heating test tubes, the outer flame of an alcohol lamp should be used. Since the test tube cannot be directly held by hand during heating, the test tube holder should be used as a tool. When using a test tube clamp to pick up a test tube, the test tube clamp should be placed from the bottom of the test tube to the upper part of the test tube, and if the length of the test tube is divided into three parts, the test tube holder should be used." It is reasonable to clamp the test tube clamp within one-third of the area near the test tube mouth. However, this is not a mandatory requirement and there is no need to rigidly copy it during the experiment.

Before heating& Nbsp; First, keep the test tube dry and preheat it before formal heating to fry. When heating, keep the outer wall of the test tube free of water droplets to prevent uneven heating and bursting. After heating is completed, wait for the test tube to cool before cleaning