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A cooling bath or ice bath, in laboratory chemistry practice, is a liquid mixture which is used to maintain low temperatures, typically between 13 °C and −196 °C. These low temperatures are used to collect liquids after distillation , to remove solvents using a rotary evaporator , or to perform a chemical reaction below room temperature ...
Dry ice: Ethylene glycol-15 Ice: Sodium chloride-20 1 to 3 ratio of salt to ice. Dry ice: Tetrachloroethylene-22 Dry ice: Carbon Tetrachloride-23 Dry ice: 1,3-Dichlorobenzene-25 Dry ice: o-Xylene-29 Liquid N 2: Bromobenzene-30 Dry ice: m-Toluidine-32 Dry ice: 3-Heptanone-38 Ice: Calcium chloride hexahydrate -40 1 to 0.8 ratio of salt to ice ...
In practice, a mechanical freezing process is usually used instead due to cost. There has been continuous optimization of the freezing rate in mechanical freezing to minimize ice crystal size. [2] Flash freezing techniques are also used to freeze biological samples quickly so that large ice crystals cannot form and damage the sample. [5]
A cold finger is a piece of laboratory equipment that is used to generate a localized cold surface. It is named for its resemblance to a finger and is a type of cold trap . The device usually consists of a chamber that a coolant fluid (cold tap water, or perhaps something colder) can enter and leave.
In chemistry, a condenser is laboratory apparatus used to condense vapors – that is, turn them into liquids – by cooling them down. [1] Condensers are routinely used in laboratory operations such as distillation, reflux, and extraction. In distillation, a mixture is heated until the more volatile components boil off, the vapors are ...
Fractional freezing is a process used in process engineering and chemistry to separate substances with different melting points. It can be done by partial melting of a solid, for example in zone refining of silicon or metals, or by partial crystallization of a liquid, as in freeze distillation, also called normal freezing or progressive freezing.
Liquid nitrogen is only used when dry ice or other cryogenic approaches will not condense the desired gasses since liquid nitrogen will also condense oxygen. Any oxygen gas content in the vacuum line or any leak in the vacuum line will result in liquid oxygen mixed with the target vapors, often with explosive results.
In chemistry a cooling bath may be used to control the temperature of a strongly exothermic reaction. A frigorific mixture may be used as an alternative to mechanical refrigeration. For example to fit two machined metal parts together, one part is placed in a frigorific mixture, causing it to contract so that may be easily inserted into the ...