today, it finally snowed in Xiaobian's city. Does the snowflake look very romantic? In cold winter, snow is a very common thing for the north. Do you know what it is like to see some vehicles sprinkle salt on the road every snowy day? In snowy days, salt is sprinkled on the road to prevent the road from freezing and slipping.
This is to increase the concretion, which is similar to the principle of artificial rainfall. When the dry ice (solid carbon dioxide) is hit into the air, the heat absorption can reduce the temperature and increase the supersaturation of water vapor in the dark cloud when the dry ice melts. The other function is to provide the concretion and make the water vapor into raindrops.
In addition, the boiler is usually equipped with some ceramic chips to provide condensation. Without these ceramic chips, the water temperature in the boiler is very high and will not become bubbles for heat dissipation. The water temperature may be far higher than 100 degrees, which will eventually cause explosion.
If the salt is not sprinkled, the environment temperature is not easy to melt even if it is higher than 0 ℃. After the salt is sprinkled, the concretion is provided. If the temperature is slightly higher than 0 ℃, it will start to melt. In addition, the melting point of the brine solution is generally lower than 0 ℃. The combination of the two causes makes the salt sprinkle easier to melt snow. (if the solution contains 20% salt, its freezing point will be reduced to - 16 ℃. Taking advantage of the characteristics of low salt freezing point, salt can be used to prevent road surface and airport runway from freezing in cold winter. )
In addition, the chapter on steam pressure in university chemistry introduces that: in fact, snow is melting and solidification, but the speed of the two is the same, so it always remains solid! We all know that the freezing point of saltwater is lower than that of water. After salt is sprinkled, the water around snow will become saltwater, so it can not be solidified! In this way, snow will continue to melt, but can not be solidified again, so it will become more and more The less!
In addition, the biggest characteristic of salt is water absorption (for example, the clothes we wear with sweat are easy to be wet, which shows that salt has strong water absorption), but salt will melt when it is sprinkled on snow. Another important condition is that the temperature of the salt being sprinkled is much higher than that of snow, Because most of the salt is stored indoors. The analogy is that the snow on the salt heap in the salt field is not easy to melt, which shows that the temperature of the salt we sprinkle is already high and the temperature of the snow, which is the condition for the snow to melt.