In an ice cream maker, a mixture of cream, milk and sugar is placed in a container that is surrounded by a bed of ice. The ice, however, is not cold enough to turn the mixture into a tasty solid form. Adding table salt (sodium chloride) to the ice lowers the freezing point and causes some of the ice to melt. This makes the temperature fall sufficiently to freeze the ice cream. In a similar manner, salt is used in many other freezing and refrigeration processes.
There are many types of salt. Calcium chloride (CaCl2) is one type of salt that is used as a road deicer. When CaCl2 is spread on ice, it lowers the freezing point of water below 0°C, so the ice turns into its liquid form, which is much safer to drive on.
|Temperature (°C) of ice in cups||Water Volume (ml)|