CHEMISTRY OF ARTIFICIAL SNOW

Madeline Welch

Summary Artificial snow is used

on ski slopes, movie sets and decorating.

Artificial snow for ski slopes creates the same ski effect as natural snow does

Brian Rohrig said that, “more artificial snow falls on ski slopes than natural snow.”

Basic chemistry of Artificial snow

Snow made for ski slopes is made through essentially a “snow gun”

The first step is to pump water right above its freezing point through the gun with high pressure

Secondly, the gun has to give off some kind of nucleation site for the water to adhere too such as clay or dust particles

Natural snow

Natural snow forms when liquid particles freeze as they fall to the ground

The water undergoes deposition, turning from a liquid straight to a solid

This is the opposite of sublimation which we studied earlier this year

Scientists have tried to duplicate this process through artificial snow

Process of making artificial snow

The first and most important aspect of making this snow is having the correct humidity and the right temperature

The process begins with the water right above its freezing point being shot out of the gun nozzle 20-30 feet above the ground

Step 1 continued While the water is being shot out, it is

accompanied by compressed air This makes the water spread into small

droplets and spreads them over a larger area

The compressed air also helps lower the temperature because when gases expand the temperature lowers

This happens because gases have weak attractive forces between their molecules and when the molecules are pushed farther apart they lose their kinetic energy

Step 2 Depending on the temperature (15-20

degrees F), organic materials such as magnesium, calcium or clay particles can serve as nucleation sites

If it isn't cold enough, inorganic materials such as silver iodide, soaps and detergents are used to help the snow form

Once the water molecules adhere to the nucleation sites, the snow falls to the ground

New technology A newer technology

are machines that have nucleating agents in them that is produced with the water

The agents are “dead, nonpathogenic bacteria that is cultured, freeze dried into pellets and finally sterilized”

This process is becoming popular because it produces no pollution and is all natural

Implications Formation of artificial

snow enables ski resorts to have snow year round

This directly affects the economy in those parts of the world

The need for artificial snow to be made is the absence of deposition

Snow isnt only important to ski slopes, but to movie makers to make scenes more life-like

Works Cited

Ritter, Steve. "Artificial Snow." The Newsmagazine of the Chemical World 19 Jan. 2004: 72. Chemical and Engineering News. Web. 10 Apr. 2013. <http://pubs.acs.org/cen/whatstuff/stuff/8203snow.html>.

Rohrig, Brian. "Artificial Snow Powder for the Slopes." ChemMatters Dec. 2000: 10-11. Print.

American Chemical Society. "Artificial Snow Creates Winter All Year Round." ScienceDaily, 20 Jan. 2004. Web. 10 Apr. 2013.