An antifreeze is a chemical additive which lowers the freezing point of a water-based liquid. An antifreeze mixture is used to achieve freezing-point depression for cold environments and also achieves boiling-point elevation ("anti-boil") to allow higher coolant temperature. Freezing and boiling points are colligative properties of a solution, which depend on the concentration of the dissolved substance. Because water has good properties as a coolant, antifreeze is used in internal combustion engines and other heat transfer applications, such as HVAC chillers and solar water heaters. The ...