Record the results. Discuss why the salt-ice mixture produced a lower temperature than the ice with no salt added. Explain that salt has, in a sense, lowered the temperature of the mixture. When ice melts due to the presence of salt, heat is absorbed. This is called an endothermic reaction.
Salt is used to lower the temperature and increase the rate of ice melting.
For example, freight and refrigerator cars use ice and salt to cool foods. The next activity will provide one example. Activity C - Ice Cream Chemistry 1. 2.Have a student pour the ice cream mixture into a sterilized beaker, glass or metal container. Create a depression so that all but the top is surrounded by ice.