What are the cleaning and drying methods of the instrument


1. Instrument cleaning The instrument must be kept clea […]

1. Instrument cleaning
The instrument must be kept clean at all times. You should get into the habit of washing the instrument after use. The instrument is cleaned after use. Not only is it easy to clean, but also because of the understanding of the cause and nature of the residue, it is also easy to find out the method of handling the residue. For example, if alkaline residues and acidic residues are treated with acid and lye respectively, it is possible to wash away the residues. Over time, it will bring a lot of difficulties to washing.
The easiest way to clean the instrument is to scrub with a brush and decontamination powder. Sometimes detergent powder or diatomaceous earth is mixed into soap powder for better scrubbing effect. After washing, rinse the instrument with clean water. It should be noted that when washing, you can't use a bald brush or use too much force, otherwise the instrument will be punctured. Tar-like substances and carbonized residues are often not washed off with detergent powder, soap, strong acid or strong lye. In this case, chromic acid lotion is needed.

2. Drying of the instrument
In organic chemistry experiments, dry instruments are often needed, so after the instruments are cleaned, they should be dried. Here are a few simple methods of drying the instrument.
⑴ Drying in an oven: generally use an electric oven with a blower. The temperature of the oven is kept at 100~120℃. Blowing can speed up the drying of the instrument. Try to pour the water in the instrument before putting it in. The mouth should face up when the instrument is put in. If the mouth of the instrument is facing down, the dried instrument may be free of water stains, but because the water droplets flowing out of the instrument drip onto other heated instruments, it is easy to cause the latter to explode. Use crucible tongs to take out the dried instrument and place it on the asbestos board to cool; be careful not to let the very hot instrument hit the cold water or cold metal surface suddenly, so as not to explode. Thick-walled instruments, such as measuring cylinders, suction filter bottles, condenser tubes, etc., should not be dried in an oven. Separating funnels and dropping funnels must be unplugged and cocked and wiped off the grease before they can be put into the oven to dry.

⑵ Air-drying: In organic chemistry experiments, the air-drying method should be used as much as possible to dry the instrument before the experiment. After the instrument is cleaned, try to pour out the water droplets and then dry it. For example, beakers can be placed upside down in a cabinet; distillation flasks, conical flasks, and measuring cylinders can be placed upside down on the small wooden stakes of the test tube rack; the condenser tube can be clamped with clamps and placed in the cabinet upright. After being left for a day or two, the instrument is dry.
⑶ Dry with an air dryer: After the instrument is cleaned, first remove the residual moisture in the instrument, and then put the instrument on the porous metal tube of the air dryer (Figure 1.3-5). Pay attention to adjusting the temperature of the hot air. The air dryer should not be used continuously for a long time, otherwise the motor and heating wire will burn out.
⑷ Drying with organic solvent: This method can be used when the instrument with a small volume needs to be dried urgently. The cleaned instrument is washed once with a small amount of alcohol, then washed with a small amount of acetone, and finally dried with compressed air or with a hair dryer (without heating). The used solvent should be poured into a recycling bottle.