Palmitic Acid Lab Report

The temperature probe was then quickly cooled to room temperature. When this was achieved, the hot water was immediately transferred into the calorimeter. This method of keeping the temperature probe cooled before measuring a new temperature was repeated throughout the entire experiment. Temperature data was collected for 180 s while swirling the temperature inside the calorimeter. The calorimeter still contained the warm water.

The purpose of this lab was to be able to use physical characteristics to determine the identity of an unknown compound. The data from this experiment classified aluminum as metallic; ascorbic acid, paraffin, palmitic acid, sucrose, graphite, and water as molecular; sodium chloride as ionic. In order to determine this, 3 tests were conducted. The first test was to test the conductivity of each substance at room temperature. In this test, only graphite and aluminum conducted.

Next time I would not add air bubbles into the dish once the brine shrimp eggs were added in but before we put the eggs in the water. I would do this to prevent eggs from being moved from one dish to another or sucking eggs out of the dishes. When recreating the lab, I would take precautions to ensure the outcome would be as accurate as possible. These precautions would keep the data from being inaccurate. Before starting the lab I would make sure variables and controls were well defined.

In all trials, some of the precipitate was lost through the filter. Therefor all values are most likely less than the actual values due to

The boiling point range of Unknown 30A was 65.0 °C-67.2 °C. The two degrees difference in the boiling point range indicated that there were very few impurities presented in the liquid. The theoretically possible identities of the unknown were primary amines that contained higher boiling points than the range because of the higher altitude lab. However, sec-butylamine, with a boiling point of 63 °C, was included as a possible identities because it was only two degrees off of the range. Therefore, it was too early on in the experiment to eliminate a potential identity that was very close to the range.

The reaction rate changes based on temperature, so if the cold temperature or hot temperature isn’t the same for all of the trials, the reaction time won’t be either. If the temperatures are too similar, like the cold and room temperature in all three trials, there isn’t a constant temperature gap to accurately see the reaction time difference. The temperature difference between the cold, room temperature, and hot water for each beaker should be constant for all trials. The timer could also be a potential error. The time needs to be started and stopped at the same point for all of the tablets, so human error could have occurred.

The predicted and experimental responses are compared in order to validate the model and to calculate the prediction error. The prediction error was found to be below 7% indicating that the observed responses were very close to the predicted values. Percentage prediction error is useful in constituting the validity of generated equations and describes how close the predicted responses to that of actual values. The values of <15 are desirable to have closeness of the predicted values with the actual values

The system in which the experiment took place was mostly closed, so neither the composition nor number of particles changed throughout the experiment. However, there was a possibility that the humididty and temperature were not definitely controlled, despite measures taken to keep them controlled, such as keeping doors and windows closed and controlling the temperature with the air conditioner and the material of the Ideal Gas Law being plastic, which is a poor conductor. Another weakness in this lab was that it was difficult to push the syringe at the same speed for each test, due to the increasing pressure, which at the smallest volumes made it difficult to push the syringe at

Purpose: The purpose of this experiment was to determine the molar mass of unknown #43 using the derived freezing point depression. To obtain the freezing point depression, t-butyl alcohol was placed in a cold-water bath and frozen solid for a total of two runs. Then, unknown #43 was dissolved in t-butyl alcohol and placed in a cold-water bath until frozen solid. This process was repeated for a total of three runs, with the first two runs containing half of the unknown, and the last run containing the full amount of unknown.

It can be hypothesized that the water in the product affected the melting point

Materials: The materials that I will be utilizing during these experimentations are three to four ice cubes, one cup for measuring, six unblemished cups, one stopwatch, one hot water source, three tablets of Alka-Seltzer, one thermometer that measures from negative

To accurately determine this, each trial will have recorded dependent and independent variables, constants and a control. The hypothesis being researched, indicates higher temperatures allow for a rapid rate of dissolution. In this particular case with someone needing Alka Seltzer, they will feel better faster if they use hot water to dissolve the medicine before

The 11 dram vial was brought to room temperature after the data for Trial #2 was collected. For Trial #3, an additional 2.0066 grams of “Unknown C” were weighed and dissolved into the 11 dram vial. Once “Unknown C” was dissolved, the 11 dram vial was submerged into the ice bath, and the Vernier temperature probe was immersed into the 11

The actual data is the result on our experiment vs theoretical, which is based on the calculations above. I have also learned to pay more attention to draining out all of the product completely before continuing to test the experiment, as any small drop of contaminant can veer our results into a different

Abstract The unknown concentration of benzoic acid used when titrated with standardized 0.1031M NaOH and the solubility was calculated at two different temperatures (20◦C and 30◦C). With the aid of the Van’t Hoff equation, the enthalpy of solution of benzoic acid at those temperatures was determined as 10.82 KJ. This compares well with the value of 10.27KJ found in the literature.