Physical phenomena

How can salt snow melt on the road?

Salt lowers the freezing point of water because it makes it difficult for water molecules to form ice crystals together. Salt is a chemical compound of sodium and chlorine.

When salt comes into contact with water or ice, the salt crystals are dissolved and positive sodium ions and negative chloride ions are released.

These ions mix with the water molecules and ensure that they cannot come so close together that ice crystals form, even though the temperature is below freezing.

Salt disturbs balance between ice and water

There is a balance in a mixture of ice and water around the freezing point: new water molecules always come into contact with the ice. Then they are encapsulated in the ice crystals, causing them to grow.

At the same time there are also water molecules that leave the ice crystals. In an equilibrium situation, as many water molecules arrive at the ice crystals as there depart.

When salt is added, the sodium and chloride ions are not automatically absorbed into the ice crystals, but they spread over the surrounding water, where they displace the water molecules.

That means that slightly fewer water molecules are available to be included in the ice crystals, while the number of molecules leaving the crystals remains unchanged.

The result is that the ice crystals lose more water than they get and the ice melts.

Video: How Does Salt Melt Ice? (November 2019).

Popular Posts

Category Physical phenomena, Next Article

Top 10: Pioneers of medicine
History of Science

Top 10: Pioneers of medicine

1. Hippocrates: End of superstition 460 - ca. 377 BC: Hippocrates was the first physician in the modern sense of the word. He distanced himself from superstitious methods of treatment and the idea that the gods should be consulted if someone became ill. Instead, he tried to heal patients based on his experience with how the body works.
Read More
When were the first books written?
History of Science

When were the first books written?

The book has had many appearances. Already around 3000 BC. wrote the Sumerians with cuneiform script on clay tablets; the Egyptians at the same time wrote hieroglyphs on pressed papyrus strips. Only around the 5th century AD. the book appeared in the physical form that we still know today - so as a number of merged pages, held together by a cover.
Read More
Anatoli was shot in the head by a particle accelerator
History of Science

Anatoli was shot in the head by a particle accelerator

When Anatoli Boegorski now looks in the mirror, he sees two different people. One side of his face bears the signs of the 75 years he has lived, but the other side is frozen in time and does not seem to have aged a day since July 13, 1978. On this fateful summer day in 1978, the Russian scientist was the victim of a unique accident in world history.
Read More