Search results
Results from the WOW.Com Content Network
A Perkin triangle is a specialized apparatus for the distillation of air-sensitive materials. Some compounds have high boiling points and are sensitive to air. A simple vacuum distillation system can be used, whereby the vacuum is replaced with an inert gas after the distillation is complete. However, this is a less satisfactory system if one ...
The ketyl radical from sodium and benzophenone can also be used for removing both oxygen and water from inert solvents such as hydrocarbons and ethers; the degassed solvent can be separated by distillation. The latter method is particularly useful because a high concentration of ketyl radical generates a deep blue colour, indicating the solvent ...
A vapor-compression evaporator, like most evaporators, can make reasonably clean water from any water source. In a salt crystallizer, for example, a typical analysis of the resulting condensate shows a typical content of residual salt not higher than 50 ppm or, in terms of electrical conductance , not higher than 10 μS/cm .
The pressure in the system must be maintained from the pump right through the pressure vessel. In smaller systems (up to about 10 mL / min) a simple restrictor can be used. This can be either a capillary tube cut to length, or a needle valve which can be adjusted to maintain pressure at different flow rates.
Condensers with forced-circulation cooling usually employ water as the cooling fluid. The flow may be open, from a tap to a sink, and driven only by the water pressure in the tap. Alternatively, a closed system may be used, in which the water is drawn by a pump from a tank, possibly refrigerated, and returned to it. Water-cooled condensers are ...
Cooling baths are generally one of two types: (a) a cold fluid (particularly liquid nitrogen, water, or even air) — but most commonly the term refers to (b) a mixture of 3 components: (1) a cooling agent (such as dry ice or ice); (2) a liquid "carrier" (such as liquid water, ethylene glycol, acetone, etc.), which transfers heat between the ...
The method of extractive distillation uses a separation solvent, which is generally non-volatile, has a high boiling point and is miscible with the mixture, but doesn't form an azeotropic mixture. The solvent interacts differently with the components of the mixture thereby causing their relative volatilities to change.
A rotary evaporator [1] (rotovap) is a device used in chemical laboratories for the efficient and gentle removal of solvents from samples by evaporation.When referenced in the chemistry research literature, description of the use of this technique and equipment may include the phrase "rotary evaporator", though use is often rather signaled by other language (e.g., "the sample was evaporated ...