Abstract

Effect of salt on the freezing point of water

Jeremy Neo Kai Hwee, Ng Kian Ping

jeremy_neo_kai_hwee@s2021.ssts.edu.sg, ng_kian_ping@s2021.ssts.edu.sg

Abstract

Salt is usually added to the surface of the ice to make them melt faster. We are trying to find out if different salt concentrations will affect the different freezing points of tap water. Since the melting point is the same as the freezing point, we have applied this concept by finding the melting point of the solutions. To get more accurate results, we froze the temperature probes directly with the solutions in the cup. The results indicate that different salt concentrations do in fact affect the freezing point of tap water. Specifically, the freezing of the tap water decreases up to -21 degrees Celsius when the salt concentration increases to 290g of salt to 1kg of water. However, beyond the concentration of 290g to 1kg of water, the melting point increases again. By finding out the general trend of the melting point of water against the different salt concentrations, we will hence be able to find which salt concentration is able to keep water frozen for the shortest period of time. This concept can be applied when salting roads in cold weather climates, where ice is applied on icy roads to speed up the melting process of the ice on the roads.