It's very snowy in New England and the roads are very icey. One of the worst things about winter is driving on very very icy roads and walking on very slippery sidewalks. The ice is very dangerous for cars and people alike. It's especially dangerous for cars that don't have the proper grip on the tires to drive on ice, and when new drivers are driving for the first time in the winter in these dangerous conditions. Plow trucks will plow the snow away and spread salt on the roads to help take the ice and snow off the roads and make the conditions a little safer.
Salting the roads lowers the freezing point of snow and ice, converting the slippery ice to water. This past year the US covered streets with 23 million metric tons of salt. The salt doesn't make the snow disappear but instead lowers the freezing point because of something called the freezing point depression. The freezing point of water is 32 degrees Fahrenheit but when the salt is spread onto the snow that freezing point is lowered so that the water doesn't freeze until the colder temperatures. This happens because of salt's properties allowing it to dissolve in water and break it down into ions. When water freezes the ions line up into a very straight sturdy line. When salt is dissolved into the water it messes with the shape of these ions and forms them into a more hexagonal shape. This makes it less stable and therefore lowers the freezing point.
Cars on the roads also help melt ice. Their friction loosens the snow and ice and turns it into slush. As the snow turns into slush, the salt has more opportunity to dissolve into it and lower the freezing point.
The salt on roads helps driving and walking on ice but it has a detrimental effect on the environment. Because the salt dissolves into the ice it is very hard to get out of the snow. Then as the runoff water goes into rivers, lakes, and the ground it affects all the wildlife in those environments. Salt is not a harmful chemical but it has effects on living and nonliving things. The underside of cars rusts frequently because of salt erosion. Many animals can be affected because salt changes the pH of bodies of water.
To test the effect that salt has on snow…(and a treat at the end)
The Materials
2 Cups
Snow
Salt
Maple syrup or honey
Timer
The Experiment
Get two cups of snow
Spread salt onto one of the cups
Set a timer and watch to see how fast each cup melts.
As an extra experiment with the snow, I tested the freezing point of maple syrup and honey. Find some clean snow and put it in a tray in a thick layer.
Pour maple syrup or honey in a line in the snow and wait till it freezes.
Enjoy the hard candy!!! And the snow
https://lessons4littleones.com/snow-science-experiments/
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