An icy road, not a good thing in this area

[+shopthebookworm]

Yes, the roads will ice. This is a fact when it gets cold we often see the roads get salted. Why is that? Lucky you, I have the reason below so if you feel the need to think about those "scientific" things and seek answers to your questions, come in and get even more answers at the store because we have hundreds of books on science and nature. Today that section is on sale for 35% off and we will include science section from our homeschool books if you want to teach the children (or yourself) something about how things work. Knowledge is power!

 

If you live in a place that has lots of snow and ice in the winter, then you have probably seen the highway department spreading salt on the road to melt the ice.­ You may have also used salt on ice when making home-made ice cream. Salt lowers the freezing/melting point of water, so in both cases the idea is to take advantage of the lower melting point.

 

Ice forms when the­ temperature of water reaches 32 degrees Fahrenheit (0 degrees Celsius). When you add salt, that temperature drops: A 10-percent salt solution freezes at 20 F (-6 C), and a 20-percent solution freezes at 2 F (-16 C). On a roadway, this means that if you sprinkle salt on the ice, you can melt it. The salt dissolves into the liquid water in the ice and lowers its freezing point.

 

If you ever watch salt melting ice, you can see the dissolving process happen -- the ice immediately around the grain of salt melts, and the melting spreads out from that point. If the temperature of the roadway is lower than 15 F or so, then the salt really won't have any effect -- the solid salt cannot get into the structure of the solid water to start the dissolving process. In that case, spreading sand over the top of the ice to provide traction is a better option.

 

When you are making ice cream, the temperature around the ice cream mixture needs to be lower than 32 F if you want the mixture to freeze. Salt mixed with ice creates a brine that has a temperature lower than 32 F. When you add salt to the ice water, you lower the melting temperature of the ice down to 0 F or so. The brine is so cold that it easily freezes the ice cream mixture.