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Why is salt sprinkled on the road in snowy days? What salt is it sprinkled with?

Recently, the snowstorm in the North has brought great difficulties for the travel of small partners. But the snow on the road soon melted. Do you know why? It's because a layer of salt is sprinkled on snowy days. What salt is the snow remover?

Why is salt sprinkled on the road in snowy days?

After snowing, the road surface is very slippery, which is easy to cause traffic accidents. The reason why salt is sprinkled on the road surface is that a lot of heat is released after salt melts and water, which can make the snow melt as soon as possible, and it is not easy to make the ground ice. If salt and salt are sprinkled on the ice to melt and water to release heat, it will also melt the ice, so that the friction on the ground will be increased, which can reduce the occurrence of traffic accidents.

The salt is potassium chloride, and the snow is water. Potassium chloride is a water-soluble chemical. Potassium chloride dissolves in water to form potassium chloride aqueous solution, which contains potassium ion and chloride ion. When water is to be frozen, when there are chloride ions and potassium ions, chloride ions and potassium ions will destroy the crystal network structure of water, so that water can not be frozen In other words, salt keeps snow from freezing.

In addition, the chapter of chemistry about vapor pressure introduces: in fact, snow is constantly melting and solidifying, but the speed of the two is equal, so it remains solid all the time! We all know that the freezing point of salt water is lower than that of water. After salt is sprinkled, the water around the snow will become salt water, so it can't solidify! So the snow will continue to melt, but it can't solidify again, so it's less and less!

Besides, salt is cheap and pollution-free. Therefore, when it snows, salt is often sprinkled on the road surface to prevent the snow water from freezing and the salt can melt the snow.

Before or after snow?

Usually after snow. However, due to the erosion of roads caused by salt water, at present, many countries have not allowed to use the way of salting snow, but use snow melting agent to melt snow!

What salt did you sprinkle?

Generally, it's industrial salt. The main component is more sodium chloride. This salt is not the salt we eat. It's a chemical term. The product of acid-base neutralization can be salt other than sodium chloride. Its main function is to reduce the freezing point of liquid and play the role of deicing and anti icing.