Recipes for Cooling Baths

Synthetic organic experiments are conducted at temperatures ranging from -90 degrees to 200 degrees Celsius. It is important to know how to achieve and maintain the correct temperature for a reaction, especially over long time periods. Temperature should be monitored with a low-temperature alcohol thermometer.

Low Temperature Cooling Baths

Cryocool: If you have access to one, a cryocool can maintain a reaction at a set temperature (typically -40 to 20 degrees) for a long period of time.
Ice/Salt: -15 to -5 degrees
Dry Ice/Acetonitrile: -40 degrees
Dry Ice/Acetone: -78 degrees
Liquid Nitrogen/Dichloromethane: -92 degrees

See Also: The Complete List on the Hoveyda Group website.

High Temperature Reactions

Hot plate/oil bath apparatus with internal temperature control.
Solvent reflux: temperature will be the boiling temperature of the solvent.
Oil bath: Mineral oil polymerizes at ~150 degrees; for higher temperatures switch to silicone oil or a heating mantle with sand (see below).
Heating mantle full of sand controlled by a Variac. Sand is less messy than oil and high temperatures are easy to attain. Put a thermometer in the sand and then experiment with the Variac until you achieve the correct temperature.
Hot plate/water bath. Sometimes convenient for gentle heating (35-80 degrees).