What can be added to the water to prevent freezing?

Salt, ethylene glycol, snow melting agent, etc.

The principle is that as long as the concentration of salt ions in water can be increased, the higher the freezing point, the less suitable it is for freezing.

Freezing point refers to the freezing point of water at standard atmospheric pressure (1.013x10.5pa), that is, 0℃(273k). The freezing point is different at different atmospheric pressures.

If you want to estimate the freezing point under a certain pressure, you can find the answer from the phase diagram of water. It is worth noting that the freezing point of water at standard atmospheric pressure is not equal to the triple point of water-the difference between them is 0.01k.

The freezing point is also related to the purity of water. The freezing point of pure water at standard atmospheric pressure is 0℃, but when water contains impurities, the freezing point will decrease.

For example, the freezing point of seawater is lower than that of fresh water. The freezing point of seawater is closely related to the salinity of seawater. When the salinity reaches 24.695, the freezing point of seawater is only-1.332℃.

Extended data:

Precautions:

1. The inorganic snowmelt agent "snowmelt agent" with "chlorine salt" as the main component is cheap, only one tenth of that of organic snowmelt agent, but it is seriously corrosive to large public infrastructure and extremely harmful to surrounding greening plants. The common snow melting agent belongs to this category, and sodium chloride is the most used.

2. Although the main component of industrial salt is also sodium chloride, it is not as high in purity as edible salt, and may contain some impurities in different degrees, and even heavy metals may exceed the standard, which may lead to poisoning or chronic harm if eaten by human body.

There is a clear reminder on the packaging bag of industrial salt: it is not edible. Eating industrial salt to melt snow has serious consequences and cannot be eaten as a vegetable.