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>