February 10, 2016

Did you know that adding salt to an ice and water mixture actually makes it stay cooler longer? At 0°C the rate at which the ice melts equals the rate at which the water freezes. When salt is added, it lowers the freezing point. In other words a lower temperature is required to freeze the water. So it the ice initially melts, but the salt also chills the surrounding water. As the ice melts, all that cold water mixes with the water already present. Thanks to the salt, the water can reach a temperature lower than the original freezing point. Since the specific heat of water is higher than ice, the water can absorb more heat.