Ethanol-water mixtures, freezing point

Ethyl alcohol (ethanol, freezing point -114.1°C, boiling point 78.3°C, density 0.7893, flashpoint 14°C) is also named, industrial alcohol, grain alcohol, and alcohol. Ethyl alcohol is miscible in all proportions with water or with ether. When ignited, ethyl alcohol burns in air with a pale blue, transparent flame, producing water and carbon dioxide. The vapor forms an explosive mixture with air and is used in some internal combustion engines under compression as a fuel such mixtures are frequently referred to as gasohol. 

The dotted line with the open symbols on the right side of the diagram is the freezing curve of ethanol in tire mixture. As one passes downward through this curve, solid ethanol precipitates from the solution. Note that the temperature at which ethanol begins to freeze decreases as the amount of water in the solution increases. Therefore, we see that the addition of impurities decreases the freezing temperature of a substance. This phenomena is known as freezing point depression. 

Antifreeze. Any compound or mixture that lowers the freeing point of water can be referred to as antifreeze. The preponderant, commercial antifreeze is ethylene glycol diluted with water. Other organic compounds used occasionally are methanol, ethanol, and propylene glycol. The primary application is to protect automotive cooling systems from freezing. 

---