Requirements for the use of various glass instruments
One: Various pipettes, pipettes and burettes:
Uses: pipettes and pipettes are used to accurately absorb a certain amount of liquid; burettes are used for solution titration;
Precautions for use: do not heat;
The basic burette is used for containing alkali solution, and the acid burette is used for containing acid solution;
Alkaline burettes cannot hold oxidants;
For titrants that are easily decomposed by light, use a brown burette
Two: Reagent bottle:
Use rubber stoppers for alkaline substances, brown bottles for substances that are easily decomposed by light, and place the stoppers upside down on the table when using reagents;
Three: Dryer:
To prevent the cover from sliding and breaking, the overheated substances need to be cooled slightly and put in, and the desiccant is placed inside to keep the samples and products dry;
Four: beaker
When heating, it is placed on the asbestos mesh, generally not directly heated.
Precautions for storage of various glass instruments
Commonly used glass instruments: should be matched according to the type and purpose, neatly arranged in the instrument cabinet, measuring cylinder, conical flask,
The flask can be inserted upside down in the laboratory cabinet to keep it clean and dry to prevent dust from falling into it.
Clean paper strips should be lined between the plugs of the grinding mouth of the grinding instrument to prevent the plug from being stuck over time and unable to open the plug.
All kinds of glass instruments should avoid long-term moisture, so as not to corrode the glass.
Therefore, glass instruments cannot be immersed in water for a long time, nor can they be immersed in acid and alkali solutions for a long time.
Pipette: After washing and drying, wrap both ends with filter paper. If it is used for precision analysis, it should be completely wrapped and stored on a special rack.
Instruments with grinding mouth: cover the plug with a leather case before use, wash it after use, and store it after drying, lining the plug with a small piece of paper,
In case the stopper cannot be opened in the future, after removing the Vaseline from the unused arithmetic burette, line it with a piece of paper and fasten the piston with a rubber band.