Common reaction vessel

1, can be directly heated

(1) Test tube

Main uses: ① Used as a reaction container for a small amount of reagents at room temperature or under heating conditions.

② Collect a small amount of gas and puretest of gas. ③ Fill a small amount of medicine.

Usage and precautions:

(1) Can be heated directly, with the tube clamp away from the tube mouth 1/3, from bottom to top cover (to prevent contamination of drugs).

② The size of the test tube is large or small. When not heated, the liquid in the test tube does not exceed 1/2 of the volume, and does not exceed 1/3 when heated.

(3) there should be no water droplets on the outer wall before heating; Do not quench after heating to prevent tube rupture.

(4) When heating, first make the tube evenly heated, and then centralized heating, the mouth of the tube should not be faced with anyone. When heating solids, the tube should be laid horizontally, the nozzle slightly tilted downward, and solids should be laid flat on the bottom of the tube. To heat the liquid, the tube should be at a 45° Angle from the table

⑤ Can not use test tube heating melting NaOH and other strong alkaline substances.

(2) evaporation dishes

Main uses: ① Evaporation, concentration and crystallization of solution. ② Dry solid matter.

Usage and precautions:

(1) The amount of liquid does not exceed 2/3 of the volume, and the liquid should be constantly stirred with a glass rod to avoid liquid splashing.

② Can be heated directly, can not be quenched after heating.

Crucible tongs should be used to remove the evaporating dish and put it on a tripod.

(3) Crucible

Main application: used for high temperature burning of solid matter.

Usage and precautions:

The crucible is directly heated on the mud triangle on the tripod, and cooling should be avoided.

② Take and place crucible or crucible cover crucible clamp.

After heating, it can be cooled in a dryer or asbestos net.

④ Should be based on the nature of heating materials, crucible of different materials, porcelain crucible is easy to be hot alkali corrosion, melting NaOH and other strong alkaline materials with iron crucible.

2, mat asbestos mesh can be heated

(1) Beaker

Main uses: ① Used as a container for solid substance dissolution and liquid dilution.

② Used as a container for reaction of large quantities of reagents.

③ Used for filtration, dialysis, fountain and other experiments, used for air tightness test, tail gas absorption device, water bath heating, etc.

(4) a cold dry beaker can be used to check whether water is generated in gas combustion; Beakers coated with clear lime water can be used to test gases.

Usage and precautions:

① The commonly used specifications are 50mL, 100mL, 250mL, etc., but the liquid is not measured in a beaker.

(2) it should be heated on the asbestos net, or heated with water bath, so that it is heated evenly; When heating, there should be no water droplets on the outside wall of the beaker, so the liquid can not be steamed dry, and the hot beaker can not be suddenly cooled.

③ When the liquid is heated, it is advisable not to exceed 2/3 of the beaker volume.

④ In the process of dissolving or diluting, do not touch the bottom or wall of the cup when stirring with a glass rod.