Lab freezing bath temperatures
Freezing mixtures in the lab are often made from a mixture of either liquid nitrogen or dry ice with a solvent. If using liquid nitrogen this forms a slurry. The viscosity of this slurry is dependent on the solvent or mixture of solvents used. If using dry ice, you generally end up with an equilibrium where a small amount of dry ice is sat in a cold bath of solvent. By varying the solvent used, different temperatures can be achieved.
There has been lots of good work done in the past in determing the temperatures of these baths and there are links for further reading in the references below.
Important combinations in a biochemistry laboratory are highlighted.
| Mixture | Temperature (°C) |
|---|---|
| p-Xylene/Liquid nitrogen | 13 |
| p-Dioxane/Liquid nitrogen | 12 |
| Cyclohexane/Liquid nitrogen | 6 |
| Benzene/Liquid nitrogen | 5 |
| Formamide/Liquid nitrogen | 2 |
| Aniline/Liquid nitrogen | -6 |
| Cycloheptane/Liquid nitrogen | -12 |
| Benzonitrile/Liquid nitrogen | -13 |
| Ethylene glycol/Dry ice | -15 |
| o-Dichlorobenzene/Liquid nitrogen | -18 |
| Tetrachloroetane/Liquid nitrogen | -22 |
| Carbon tetrachloride/Liquid nitrogen | -23 |
| Carbon tetrachloride/Dry ice | -23 |
| m-Dichlorobenzene/Liquid nitrogen | -25 |
| Nitromethane/Liquid nitrogen | -29 |
| o-Xylene/Liquid nitrogen | -29 |
| Bromobenzene/Liquid nitrogen | -30 |
| Iodobenzene/Liquid nitrogen | -31 |
| Thiophene/Liquid nitrogen | -38 |
| 3-Heptanone/Dry ice | -38 |
| Acetonitrile/Liquid nitrogen | -41 |
| Pyridine/Liquid nitrogen | -42 |
| Acetonenitrile/Dry ice | -42 |
| Chlorobenzene/Liquid nitrogen | -45 |
| Cylcohexanone/Dry ice | -46 |
| m-Xylene/Liquid nitrogen | -47 |
| n-Butyl amine/Liquid nitrogen | -50 |
| Diethyl carbitol/Dry ice | -52 |
| n-Octane/Liquid nitrogen | -56 |
| Chloroform/Dry ice | -61 |
| Chloroform/Liquid nitrogen | -63 |
| Methyl iodide/Liquid nitrogen | -66 |
| Carbitol acetate/Dry ice | -67 |
| t-Butyl amine/Liquid nitrogen | -68 |
| Ethanol/Dry ice | -72 |
| Trichloroethylene/Liquid nitrogen | -73 |
| Butyl acetate/Liquid nitrogen | -77 |
| Acetone/Dry ice | -78 |
| Isopropanol/Dry ice | -78 |
| Isoamyl acetate/Liquid nitrogen | -79 |
| Acylonitrile/Liquid nitrogen | -82 |
| Sulfur dioxide/Dry ice | -82 |
| Ethyl acetate/Liquid nitrogen | -84 |
| Ethyl methyl ketone/Liquid nitrogen | -86 |
| Acrolein/Liquid nitrogen | -88 |
| Nitroethane/Liquid nitrogen | -90 |
| Heptane/Liquid nitrogen | -91 |
| Cyclopentane/Liquid nitrogen | -93 |
| Hexane/Liquid nitrogen | -94 |
| Toluene/Liquid nitrogen | -95 |
| Methanol/Liquid nitrogen | -98 |
| Diethyl ether/Dry ice | -100 |
| n-Propyl iodide/Liquid nitrogen | -101 |
| n-Butyl iodide/Liquid nitrogen | -103 |
| Cyclohexane/Liquid nitrogen | -104 |
| Isooctane/Liquid nitrogen | -107 |
| Ethyl iodide/Liquid nitrogen | -109 |
| Carbon disulfide/Liquid nitrogen | -110 |
| Butyl bromide/Liquid nitrogen | -112 |
| Ethyl bromide/Liquid nitrogen | -119 |
| Acetaldehyde/Liquid nitrogen | -124 |
| Methyl cyclohexane/Liquid nitrogen | -126 |
| n-Pentane/Liquid nitrogen | -131 |
| 1,5-Hexadiene/Liquid nitrogen | -141 |
| Isopentane/Liquid nitrogen | -160 |
Cooling baths.pdf (below) contains the original Rondeau paper cited below along with other information regarding making cooling baths with liquid nitrogen, dry ice and salt solutions.
Download Cooling baths.pdf (1.04 MB)
References
http://es.ucsc.edu/~silab/CoolingBathComposition.phpRondeau, R.E. (1966) Slush baths. J. Chem. Eng. Data, 11: 124.
First published on 9th November 2010 and last modified on 25th June 2011.
