How alcohol lamps heat substances

1. In heating with alcohol lamp can use test tubes, flasks, beakers, evaporation dishes to heat the liquid, dry test tubes, evaporation dishes, etc. can be used when heating solids, some instruments such as gas collection cylinders, measuring cylinders, funnels, etc. are not allowed to be heated with alcohol lamps. (Beakers and flasks should not be heated directly on a flame, but should be heated on an asbestos net)

2. If there is water on the outer wall of the heated glass container, it should be wiped clean before heating, and then heated to avoid the container from bursting.

3. When heating, do not make the bottom of the glass container contact with the wick, do not be far away, too close or too far will affect the heating effect, burn very hot glass containers, do not immediately rinse with cold water, otherwise it may break, do not immediately put on the test bench, so as not to burn the test bench.

4. To heat the solid in the test tube, it should be preheated, and the method of preheating is: move the test tube back and forth on the flame, move the alcohol lamp for the fixed test tube, and then fix the lamp flame in the part where the solid is heated after the test tube is evenly heated.

5. Heat the liquid in the test tube and also preheat. At the same time, pay attention to the liquid volume is best not to exceed 1/3 of the volume of the test tube, when heating, make the test tube oblique a certain angle (about 45 °), in the heating to move the test tube from time to time, in order to avoid the liquid in the test tube boiling spray out of the injury, heating must not be the test tube mouth towards their own and human direction, the test tube clamp should be clamped in the upper middle part of the test tube, the hand should hold the long handle part of the test tube clamp, so as not to press the short handle with the thumb, causing the test tube to fall off.

6. Pay special attention to the fact that it should be set from the bottom of the test tube to the top when clamping, and should also be withdrawn from the bottom of the test tube when it is removed.