Eksikator (from the Latin. Exsiccare "dry") - a vessel in which a certain air humidity is maintained (usually close to zero), made of thick glass or (less often) plastic. The lid of the exsiccator is ground to the plane of the upper edge of its body and is lubricated with special vacuum grease or petroleum jelly to achieve tightness [1] .
Desiccators are used for slow drying at room temperature, storage of hygroscopic compounds, in gravimetric analysis , when it is important not to allow the test substances to saturate with an unspecified amount of water from the air, as well as in soil science to take the OGH curve . For some purposes, it is possible to create a vacuum inside the desiccator.
The desiccator has a special shape to accommodate the lattice porcelain tray on which the cups are installed. At the bottom of the desiccator is placed a hygroscopic substance for drying or a solution that maintains a certain partial pressure of water vapor .
It is necessary to open the desiccator by moving the lid, rather than lifting it, because otherwise the case can be lifted with subsequent separation and destruction. Transfer desiccator should, holding the lid with your thumbs to prevent it from slipping. When placing hot crucibles and other objects in the desiccator, the lid should be left ajar so that when they cool down, the pressure does not drop to a level that prevents the desiccator from opening [2] .
Some types of desiccators are equipped with a tap hole for pumping air or filling the desiccator with an inert gas. Vacuum desiccators during the first pumping should be covered with a cloth or wire cage, as an explosion can occur and the fragments can spread due to manufacturing defects or glass strain [3] . Due to the risk of explosion, it is forbidden to transport evacuated desiccators [4] .
In entomology, a desiccator, on the bottom of which wet sand is poured, is used to soak the material [5] .
Notes
- ↑ Resurrection P. I. Beginning of the technique of laboratory work . - M .: Goskhimizdat, 1963. - p. 37.
- ↑ Ivanov A. B .. Desiccator Chemical tableware. Chemistry - Just . (March 21, 2018). Retrieved January 17, 2019.
- ↑ Brockhaus ABC Chemie. - Leipzig: VEB FA Brockhaus Verlag, 1965. - S. 386–387.
- ↑ Meyendorf G. Laborgeräte und Chemikalien. - Berlin: Volk und Wissen Volkseigener Verlag, 1965. - S. 21-22.
- ↑ Kozlov M., Nienburg E. Your collection. - M. , 1971. - p. 78.
Links
- Wikimedia Commons has media related to Desiccator.