PFA Volumetric Flask
Precautions:
1. The solute cannot be dissolved in the volumetric flask, the solute should be dissolved in the beaker and then transferred to the volumetric flask;
2. The volumetric flask cannot be heated. If the solute releases heat during the dissolution process, the solution should be cooled before transferring, because the bottle will expand when the temperature rises, and the measured volume will be inaccurate;
3. The volumetric flask can only be used to prepare the solution. It is not recommended to store the solution for a long time. It is recommended to use a reagent bottle for long-term storage;
4. The volumetric bottle should be washed in time after use, do not dry in an oven, just dry it with normal ventilation.
Teflon Flask
Precautions:
1. Asbestos mesh should be used for heating, or other hot baths can be used for heating. When heating, the amount of liquid shall not exceed 2/3 of the volume, and shall not be less than 1/3 of the volume;
2. When configuring accessories (such as thermometers, etc.), you should choose a suitable sealing plug and pay attention to check the air tightness;
3. Add a small amount of zeolite at the bottom of the bottle during distillation;
4. When heating, it should be placed on the asbestos net to make it evenly heated;
5. After the distillation, the piston must be closed before stopping the heating to prevent sucking back.
Teflon Condenser Tube
Precautions:
1. Do not suddenly cool and heat;
2. Cooling water enters from the low end and exits from the high end, and the water and steam flow countercurrently, so that the temperature at the end of the condenser tube is the lowest and the steam is fully condensed;
3. Straight tubes are mostly used for distillation operation. The steam temperature is less than 140 degrees and cannot be used for reflux;
4. The serpentine tube is used for reflux in organic preparation and is suitable for liquids with lower boiling points.
Teflon Separatory Funnel
Notes on the separatory funnel:
1. Check whether there is water leakage, pour the mixed liquid into the separatory funnel, and place the separatory funnel on the iron ring to stand still;
2. Open the piston of the separatory funnel, and then open the cock, so that the lower liquid (water) is released from the lower end of the separatory funnel, and the cock can be closed when the oil-water interface is tangent to the upper mouth of the cock;
3. Pour out the upper liquid (oil) from the top of the separatory funnel.