Chemistry of salt on roads
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Transcript of Chemistry of salt on roads
CHEMISTRY OF SALT ON ROADSBy Jackson Mitchell
History of Road salt
First used as an experiment in 1938 (Howard).
Used nationwide by the winter of 1941-1942 (Howard).
Road salt is not purified like table salt although both are same molecule
Key Facts
Also called “Rock Salt” 17 Million tons of salt were applied to roads
last year (Howard). Reduced crashes by 88%, injuries and
accident costs by 85% (Howard).
Freezing Point Depression
Colligative property of water (Helmenstine).
Lowers freezing point to about 15 degrees F.
Solute dissolves in the water which speeds up the water molecules, causing freezing point to decrease (Senese).
Common Substitute
Sand (Silicon dioxide) Used on roads mainly to increase tire
traction. (Senese) Used more often when temperature drops
below 15 degrees F.
Negative Effects
The road salt reacts with water, oxygen, and the metal on cars to create an increase in corrosion.
Corrosion is the gradual destruction of materials (Bruscke).
Implications
This topic can affect just about anyone, especially during Holiday travel in the winter.
Many lives have been saved due to the freezing point depression that occurs.
Without road salt roads would be extremely dangerous during winter storms.
Works Cited
Pictures Slide 1-http://
blog.nwautos.com/2010/01/hold_the_salt_how_to_fight_winter_car_corrosion_no_matter_your_budget.html
http://www.nydailynews.com/news/national/winter-storm-cripples-south-deadly-wrecks-article-1.1595039
Slide 2- http://www.dailymail.co.uk/news/article-2508731/Salt-earth-The-5-000-year-old-mines-inside-caves-tunnels-Turkey-use-today.html
Slide 3- http://www.portlanddailyphoto.com/2013_12_01_archive.html Slide 4-http://icanhasscience.com/chemistry/salting-the-roads-more-
complicated-than-it-sounds/ Slide 5- https://
sg.entertainment.yahoo.com/photos/photo-of-the-day-slideshow-slideshow/montgomery-city-workers-spread-sand-icy-roads-downtown-photo-012524668.html
Slide 6- http://ztechmichigan.com/ Slide 7- http://www.news9.com/category/119393/travel-wise
Works Cited (cont.)
New Hampshire Department of Environmental Services. "Environmental Fact Sheet of New Hampshire." New Hampshire
Department of Environmental Services. N.P., n.d. Web. 8 Apr. 2014.
<http://des.nh.gov/organization/commissioner/pip/factsheets/wmb/documents/wmb-4.pdf>.
Helmenstine, Anne Marie. "Melting Snow & Ice with Salt." About.com Chemistry. N.p., n.d. Web. 13 Apr. 2014.
<http://chemistry.about.com/cs/howthingswork/a/aa120703a.htm>.
General Chemistry Online. "Why does salt melt ice?" General Chemistry Online: FAQ: Solutions:. N.p., n.d. Web. 11 Apr.
2014.<http://antoine.frostburg.edu/chem/senese/101/solutions/faq/why-salt-melts-ice.shtml>.
National Geographic. Howard, Brain. “The Surprising History of Road Salt.” N.p., n.d. Web. 12 Feb. 2014.< http://
news.nationalgeographic.com/news/2014/02/140212-road-salt-shortages-melting-ice-snow-science/
Bruscke, Kate. "How Does Metal Corrode?" eHow. N.p., n.d. Web. <http://www.ehow.com/how-
does_4676279_metal-corrode.html>