General washing steps for glassware
Various glass instruments are used in the experiment. Whether these glass instruments are clean or not will directly affect the accuracy of the experimental results. Therefore, the glass instruments must be cleaned before the experiment.
General glass instruments, such as beakers, flasks, conical flasks, test tubes and measuring cylinders, can be washed with water from the outside to the inside with a brush, so that water-soluble substances, some insoluble substances and dust can be washed away; if there are organic substances such as oil stains , can be washed with detergent powder, soap powder or detergent. Scrub with a brush dipped in decontamination powder or detergent, then rinse with tap water, and finally rinse the inner wall with distilled or deionized water 2 to 3 times. The inner wall of the cleaned glassware should be evenly wetted by water without water streaks and without water droplets. In organic experiments, glass instruments with grinding mouths are often used. When washing, care should be taken to protect the grinding mouths. It is not appropriate to use detergents instead of detergents.
For glass instruments that are not easy to clean with a brush or are not clean with a brush, such as burettes, volumetric flasks, pipettes, etc., usually pour the detergent into or soak in the container for a period of time, and then wash the container. The agent is poured into a storage bottle for later use, and then rinsed with tap water and deionized water.
The sand core glass filter must be cleaned immediately after use. According to the different sediments remaining in the sand core of the filter, use an appropriate detergent to first dissolve the solid precipitated on the surface of the sand core, and then use the vacuum pumping method to repeatedly wash the sand core with detergent. All the remaining sediments were removed by suction, then rinsed with distilled water, dried at 110°C, and stored in a dust-proof cabinet.