why does salt melt snow on roads?
In: Chemistry
It doesn’t really. It stops the freezing process. Salt decreases the temp that water freezes at. The more salt the lower the temperature. I can’t describe the exact mechanics of why it works but I can give you the equations for how the concentration effects the temp difference if you are interested.
Water molecules like to stick to each other, but they can also stick to other things. Heat makes them stick to each other less, but other things can do that too.
When there’s a medium amount of stickage to other water molecules, water is it’s a liquid. When there’s a lot of stickage to other water molecules, water is a solid (ice.) When it gets cold, that makes more stickage to other water molecules happen, so water freezes into ice.
Water *really* likes to stick to salt tho. So when you throw some salt on ice, it decreases the stickage to other water molecules because it wants to stick to the salt instead. Since there’s less stickage to other water molecules, it melts into water even though its colder than the temp it would normally freeze at if there was no salt to stick to.
Adding salt lowers the freezing point of water by disrupting the hydrogen bonds that create the ice. It can still freeze in very low temperatures but most types of salt work pretty well 15-20 degrees below the freezing point.
The salt lowers the freezing point of water thus making the snow melt. However it won’t work at near 0 degrees F.
Bc salt water has a lower freezing point than pure water. So adding salts will melt the ice.
It doesn’t. The top layer of ice is continually melting and refreezing, so the salt doesn’t actually melt the snow or the ice, it interrupts its ability to refreeze.
[https://www.thoughtco.com/why-does-salt-melt-ice-607896](https://www.thoughtco.com/why-does-salt-melt-ice-607896)
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