Sodium Chloride Lab Report

1. Sodium Chloride has a higher boiling point than water, so when salt is added to water, the solution has a higher boiling point than pure water. The sodium ions and chloride ions present in sodium chloride disassociate and dissolve in water. These ions interfere with the dipole interactions that occur between molecules of water. The dissolved sodium ions and chloride ions require more energy to separate from the water molecules in the solution than the water molecules from themselves, so the boiling point of the solution is elevated as a result.2

2. The compounds and solvents used have fairly low melting points, so the use of a Bunsen burner would likely result in irreversible changes (ex: combustion) to the some of the compounds/solvents.

The three remaining trials were the experimental groups containing Benzoic Acid and Camphor separately with tert-butanol. 6.305 of tert-butanol was placed in a large test tube, the same amount was used for each trial. The solution was then brought to 50 C using a hot-plate. The temperature was monitored and recorded by a Lab Quest 2 Connected Sciences System. The test tube was held in place using test-tube tongs, and the thermometer was suspended in the solution to ensure accurate measurement. The solution was brought to 50 C, and then the temperature was then recorded at 10 readings per second. After several readings were recorded, the test tube with the solution in it was placed in an ice water bath. The temperature of the solution was monitored for several minutes at 10 readings per second in the ice water

This implies that the vapor pressure of both benzoic acid and camphor are significantly greater than the vapor pressure of tert-butanol. In trial 4 there were less moles of camphor present than in either trial of benzoic acid, yet it had a similar effect on the freezing point of tert-butanol (Figure 3). This supports that camphor has a much higher vapor pressure than both tert-butanol and Benzoic acid. When benzoic acid was added to the solution in trial 3 in greater amount than trial 2, the temperature change was greater, further supporting that benzoic acid has a higher vapor pressure than tert-butanol. This is supported by the data, the experimental groups all reached greater temperatures, and remained liquids at lower temperatures (Figure 3). The accuracy of that recorded data may have been impacted by human error. The actual freezing points of the solutions were difficult to determine accurately due to the equipment used, although the trends overall trends of the experiment were still visible. The method of temperature measurement may have affected the outcome of the experiment. The temperature attachment for the Lab Quest 2 system was held in the test tube by hand, and likely came into contact with the test tube the solution was in. The test tube likely