Reducing Ice Lab Report

This reports presents the process of answering the following question, is sodium chloride a viable option for reducing ice on Minnesota roads? The answer to this question relies heavily on how well sodium chloride decreases the freezing point when dissolved in water, as well cost and its environmental impact. To determine this, the freezing point of varying molality’s of sodium chloride were compared to pure deionized water. The results of this experiment revealed that as more sodium chloride was dissolved, the freezing point depression increased. These values were anywhere from -1.14 and -4.51 degrees Celsius. Another strong indicator of sodium chlorides ability to deice roads is its enthalpy of dissolution. An exothermic reaction is preferred

To determine this, multiple tests were conducted to compare how the addition of sodium chloride in varying amounts effects the freezing point of water. To have a control in the experiment and to also test the accuracy of the temperature probe, the freezing point of deionized water was first determined. A 50 mL beaker was used to measure out 10mL of deionized water. This water was then emptied into a 6 inch graduated cylinder and set aside. A Vernier temperature probe was attached to the computer with GoLink! interface. A computer program, LoggerPro, was used to monitor the data from the temperature probe. Once the computer was set and ready to go, a 400 mL beaker was filled to the top with crushed ice. 5.0 grams of rock salt was sprinkled over the top of the ice. The rock salt lowers the temperature of the ice, allowing for quicker freezing of the samples in the graduated cylinders. The 6-inch test tube containing the 10 mL of deionized water was then placed into the “ice bath” in the 400 mL beaker. The temperature probe was then inserted into the 6 inch gradated cylinder. LoggerPro began collecting temperature data points every 10 seconds. These data points were displayed on a graph, where lab members watched for indications of freezing. These indicators include plateaus and sudden spike increases in the temperature, and visual

To determine sodium chlorides enthalpy of solution, samples of sodium chloride were dissolved in water as the temperature of the solution was monitored with a temperature probe. 1.0 grams of sodium chloride was weighed out on an analytical scale and set aside. Using a 100 mL beaker, 50 mL of deionized water was measured out. The 50 mL of deionized water was then transferred to a calorimeter. The calorimeter consisted of one Styrofoam cup in the other, capped with a thick piece of Styrofoam. A Vernier temperature probe was attached to the computer with GoLink! interface. The computer software used to interpret and monitor the temperature readings was LoggerPro. LoggerPro was set to collect a temperature reading from the calorimeter every 3 seconds. The initial temperature of the deionized water in the calorimeter and recorded. The 1.0 grams of sodium chloride was then added to the 50 mL of deionized water, the calorimeter cap was placed quickly, and the temperature probe inserted through a small hole in the cap. The temperature was monitored until steady as the solution was stirred with the temperature probe. This procedure was replicated twice more for a total of three trials. Following these experiments, the procedure was replicated again with the exception of using 2.0 and 3.0 grams of sodium chloride instead of 1.0 grams described