Cooling Solutions & Mixtures

An alternative to using an ice bath, peltier cooler or recirculating chiller to cool a solution is to prepare a solution whose freezing point is far below that of water. Here are a few salt mixtures which may be used in the laboratory as "cooling - bath" solutions. 

• Sodium chloride and crushed ice. * ~ 1 part salt + 3 parts crushed iced.  Good for cooling down to -21C.
• Potassium chloride and water. * ~ 1 part salt + 4 parts water. Good for cooling down to -11C.
• Calcium chloride (CaCl2*6H20) and water. *  ~ 2 parts salt + 1.4 parts crushed ice. Good for cooling down to ~ -55C.