Make a freezing mixture by adding salt to water | Water | Physics

Adding salt to water reduces its freezing point, making it possible to lower the temperature of water below its normal freezing point without turning it to ice. This activity compares the behaviour of ice in regular water and salt water and shows that ice melts at a slower rate in salt water. Before refrigeration, such freezing mixtures were once a big industry used for cooling, food preparation and transport. Even today, freezing mixtures remain useful for small scale operations or in areas where electricity is not available.