Through three different experiments we were to find the quality of NaCl as a deicer. These experiments included testing the freezing point depression of NaCl in solution at two different concentrations, testing for the H of an aqueous NaCl solution, and combining NaCl with MgCl2 in an aqueous solution to test for freezing point depression. Through these various experiments we found NaCl to be the best deicer for our region due to its proficient freezing point depression and its cost efficiency.
As scientists we were given the task to find the overall effectiveness of NaCl as a deicer. In choosing the best deicer we are comparing NaCl to KCl, MgCl2, and CaCl2. We believed NaCl to be the best deicer as it is well know that NaCl is quite commonly used in the United States as a deicer on roads and sidewalks during the winter. To determine whether or not NaCl is the best deicer we administered three days of separate experiments. These experiments helped us to find our deicer’s maximum freezing point depression, its H, and its overall efficiency as a deicer. The information obtained through these experiments is crucial to public safety during the winter as the ability to melt ice on roads can be the difference in saving someone’s life. Also, to have an efficient deicer that is proficient in the conditions needed, and is economically savvy for whoever is supplying the salt for these roads is essential when testing for deicing quality. There has been a lot of work done previously to find the most efficient deicer. We have been using salt to control snow and ice on roadways since 1930. However, we are now looking into the environmental effects of salts as deicers along with other potentially harmful effects. One current study is looking into the corrosive effects of salts on our vehicles. Experimental
Our experiments began on day one by filling a 400ml beaker with ice and an arbitrary amount of rock salt in order for our ice bath to reach sub-zero degree temperatures. We then measured 10ml of deionized water using a 10ml graduated cylinder and combined 0.25g NaCl with the water in a test tube. The test tube was then submerged in the ice bath. Using logger pro with the temperature probe the temperature probe was inserted into the aqueous solution and the freezing point was recorded when ice crystals are detected. We repeated these steps two more times and repeated them three more times with 0.50g NaCl and 10ml of deionized water.
As we moved on to our day two experiments we were to find the H of solution of NaCl and deionized water. We did this by constructing a calorimeter using the pink foam provided and a piece of paper to cover it. A 400ml beaker was filled with deionized water and was heated up until using a hot plate. We began with a set value of 5ml of room temperature water and arbitrary amounts of hot water being added into the calorimeter together. Using logger pro with a temperature probe we were able to find the final temperature of the two combined liquids in the calorimeter. The calorimeter was covered with a piece of paper and a hole was cut in the middle in order for the temperature probe to fit in the calorimeter. These steps were repeated two more times using the other volumes of hot water. We then measured another 10ml of deionized water, recorded the initial temperature using the temperature probe with logger pro, and mixed 0.50g of NaCl with the water into a test tube. The final temperature of the aqueous solution was recorded and repeated two more times.
On day 3 we first decided to test the freezing point depression of a supersaturated solution of NaCl in 10ml deionized water. We attempted this and quickly concluded that this was not obtainable under lab conditions as the theoretical freezing point of this solution is around -22C. We then concocted mixture of 0.25g of NaCl and 0.25g MgCl2 in 10ml of deionized water. We repeated the steps...
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"Deicing." The Environmental Literacy Council -. N.p., n.d. Web. 07 Mar. 2013.
"Melting Snow & Ice WithÂ Salt." About.com Chemistry. N.p., n.d. Web. 07 Mar. 2013.
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