In accordance with the general definition the freezing point is the transition temperature from liquid to solid state.This characteristic depends on what substance is cooled (composition) and what pressure, asthe higher the pressure, the higher freezing temperature.The most well-known substance that is most often transferred from liquid to solid and vice versa, is water.It is known that ordinary water becomes ice at zero degrees Celsius, but the ultra-pure H 2 O in a clean container can be liquid and in the bitter cold, as well as the sea, comprising a plurality of salts.
Other liquids have different levels of performance.For example, the freezing temperature much lower alcohol such as index for ordinary water.This is due to the fact that this substance has a lower density.
total there are several groups of alcohols, each of which has its physical and chemical properties.Today they are the following classes:
- depending on the number of hydroxyl groups (from monohydric to polyhydric alcohols);
- depending on whether saturated hydrocarbon substituent (unsaturated, limit, aromatic);
- depending on a cyclic hydrocarbon substituent (alicyclic cyclic);
- by the number of substituents on the alpha carbon atom (primary - tertiary).
For example, the freezing point of alcohol methanol relating to monohydric, is minus 97 degrees Celsius, and cyclohexanol - about minus 42oS.However, most often it appears in the search engines query regarding the properties of the liquid, which is part of alcoholic beverages.Freezing of ethyl alcohol (ethanol) is minus 114 degrees Celsius.This property is used in the home to highlight the alcohol component of alcohol beverages in order to "increase the degree", as well as for the production of winter "nezamerzayki" for cars.Some motorists added to a glass-ethanol solutions summer type or mixed with water in certain proportions.
Note that not all of the liquid in this class pass into the solid state only under very strong cooling.For example, the freezing temperature fenilkarbinola alcohol (benzyl aromatic alcohol) is minus 15 ° C.
If you ever be interested in the classification of thermometers, you can see that there are thermometers, running on alcohol-based.Ieinstead of the electronic mechanism or device contains mercury in alcohol.These thermometers are most often used where it is necessary to measure the temperature in the low living conditions.For example, in Siberia, where frequent frosts up to 50-60 degrees.Here ordinary thermometer will not work correctly because the freezing point of mercury is about minus 38 ° C.Learn about what you have a thermometer, you can color in the thermometer column.If it is silver, mercury inside.But the red bar indicates tinted alcohol solution.These thermometers are often used to measure external temperatures.Even if the street will -45oS, the unit will not fail, becausealcohol freezing point much lower.
