What to pay attention to when using glass test tubes

1. In order to facilitate shaking and prevent the phenomenon of overflowing outside the tube during boiling, the liquid medicine contained in the glass test tube should not exceed 1/3 of the volume.
2. The powdered drug can be fed into the paper slot, and the granular drug can slowly slip down along the inner wall of the glass test tube, and must not be dropped vertically to avoid breaking the bottom of the glass test tube.
3. The outer wall of the glass test tube should be wiped dry before heating to prevent the glass test tube from bursting due to uneven heating.
4. The liquid should be heated evenly, and do not fix the bottom of the heated glass test tube to prevent the liquid from spraying out. When heating, the glass test tube should be kept at an angle of 45° with the experimental table, so that the liquid will have a very large heating area and evaporation surface, so that the boiling remains uniform.
5. When heating, the nozzle is not right to prevent the liquid splashing and hurting people.
6. Solid heating should be preheated first, and then fixed heating. To prevent the condensed water from flowing back to the hot bottom and causing bursting, the glass test tube mouth should be facing down slightly.
7. The freshly burned glass test tube should be placed on the asbestos mesh and allowed to cool slowly to avoid quenching and bursting.