Based on calculations #5 and #6 made above for solving the molecular weight, it was identified that the third unknown volatile liquid was Heptane: 100.20g/mol. Since the observed value was 104.8g/mol, it was assumed that Heptane was the only gas out of all that were listed that shared a similar value. Supported by table 2 and 3 the average molecular weight of acetone and the unknown volatile liquid was calculated to be approximately, 154.5g/mol and 104.8g/mol, respectively. The molecular weight (MW) for both acetone and the unknown volatile liquid was unsuccessfully proven to match the accepted values of 58.08g/mol and 100.20g/mol, respectively. More specifically, this was evident due to the percent error that was calculated, approximately …show more content…
It is possible that the discrepancy of the molecular weight of both acetone and the unknown volatile liquid was caused by the deviation of mass in each trial. During the trial of the experiment aluminum foil was used as a cap for the Erlenmeyer flask and by using a pin, a hole was made into the cap to insure that the gas vapors would escape during the heating process, later the Erlenmeyer flask was measured after the heating process when the gas was fully condensed; however, this procedure effected the results collected. With the usage of the aluminum foil it had resulted the presence of excess moisture build up from the water bath which then had increased the mass of the gas that had been condensed due to it being measure with both the foil and elastic band. Since, the Erlenmeyer flask was left behind with the water moisture contained in the foil; therefore, it had affected the final mass of the condensed vapor inside the flask. Although the procedure was effective and adequate results were obtained, there are some improvements that can be made towards the experiment to make it exceptional. Instead of using the aluminum foil as the cap for the Erlenmeyer flask it would be suggested to use a rubber stopper that contains a pinhole, this way it would be much easier to dry the cap to …show more content…
The steps that were taken involved using an analytical scale to weigh the Erlenmeyer flask containing no liquid in it (in grams) and filling the entire Erlenmeyer flask with water. Again, separately weighing its mass (in grams) and recording this value as the total mass/ final mass. Altogether, this gives the value of the mass of the liquid inside the flask because mass liquid = final mass – initial mass. Later, it was assumed that the density ratio of water is 1 gram = 1 mL. Using the density formula; density = mass(g)/volume(mL), rearranging would give the value of volume of the Erlenmeyer flask (in mL), simply by dividing the mass of liquid from the density of water. Altogether, this procedure was effective because the values for both flasks one and two were similar to one another in value, which makes sense because both were 50mL in size, as seen in calculation
The slight increase changes in mass were due to the increase of pennies. The property of density which is independent of the amount or size of the material used to find out what actually caused the change in mass. The slope of linear fits for the mass and volume graph gives us the average density for the pennies. The hypothesis was accepted because the data supports that the more pennies added increased the volume. The laboratory experiment worked very well.
The temperature probe was connected to the LabQuest pro. After, string was cut and a piece of filter paper was placed on the tip of the temperature probe. The string was used to tie the filter paper to the tip of the temperature probe. The probe was then placed in a container of liquid based on its group. Alkanes: Pentane, Hexane, Heptane; Alcohols: Methanol, Ethanol, 1-Propanol, 2-Propanol, 1-Butanol; Misc: Water, Acetone.
Now we place into the Erlenmeyer flask filled with Na2SO3 (aq), 30ml of 0.3 mol/L solution of HCl. 6. Right after mixing the two solutions, we quickly put the cap on the flask so that all of the gas produced is transferred through the glass tubes into the measuring cylinder. 7.
Looking at this value, and comparing the experimentally determined values, the values do not exactly match up, but are close together, as the values are only 0.4 - 0.6 g/mL away from the value of 1 g/mL. One reason why the values may not match up is because of the amount of liquid used. Sometimes, the value of water poured into the graduated cylinder may not be equal to specific volume which was to be used. In order to improve that, making the water volume more precise may allow for more accurate results. Secondly, the type of water used may of affected the value. If we take a look at pure water, the value of it at room temperature is 0.99823 g/mL. If we use this water (by boiling it before hand), and confirming the density is equal to the accepted value, than it will increase the chance of being more accurate.
The experimental density was then compared to the actual value and a percent error was determined. Materials: Equipment and materials used in this experiment were: unknown metal samples (2) 100 mL graduated cylinder electronic balance tap water wire screening weigh dish (Dixie cup) Methods: The mass of five different amounts of an unknown metal sample was determined using an electronic
The object was dried with a paper towel to avoid any water droplets and the mass balance was checked to read 0.0 g when nothing was on it. The first measurement that was retrieved as the mass of the metal object was 24.15 g. This was repeated for a second measurement of 23.85 g, and a final measurement of 23.82 g. All three mass measurements were recorded. Moving forward, to find the volume of the metal object, the graduated cylinder
This heating and cooling was repeated until there was very little (less than 0.0010 grams) fluctuation in numbers. Vial one had a start weight of 14.7681 and an end weight of 15.4098, meaning the mass of the water was 0.4658. Vial 2 had a start weight of 14.7451 and an end weight of 15.3833, meaning the mass of the water in this sample was 0.4633. The mass of the water was found by subtracting the mass of the vial with the hydrate (the start weight) from the mass after the final heating (the final weight). To then find the percent water divide the water mass by the hydrate mass and multiply by 100 since the number is a percent.
Once the mixture was distilled into the three fractions an IR machine analyzed the results. The hypothesis was not supported by the employed methods. Introduction: Distillation is the method of boiling a liquid followed by condensing the vapors and collecting the condensation (Mayo,
RESULTS In my experiment I found that the realtivity between densities and temperature corispond to each other. I first found the densities of all 5 liquids.. I first found how much my cylinder that i was going to measure my liquids in weighs. I did this because when i go to measure my other liquids i have subtract the weight of the cylinder to get an accurate measurement for the liquid.
In addition, the first .5 mL of distillate collected in each distillation was run under a GC. As seen in GC analysis of the distillate collected via fractional distillation in figure 1 , the GC detected acetone, hexane, and toluene with retention rates of .602, .673, and .875 min respectively. This was similar to figure 2 using simple distillation. The retention rates of acetone, hexane, and tuolene were .602, .676, and .882 min respectively. Since hexane had a lower retention time than toluene, this means it eluted quicker.
Procedure • As described in the lab manual (CHM 1321 Organic Chemistry Laboratory Manual, Dr. Tony Durst et. al. , Sept. 2013, Exp.2, pg. 20-27.) • Replace the receiving flask with a graduated cylinder for better measurement of the distillate.
The point of the experiment was to test how accurate and precise five pieces of lab glassware--an erlenmeyer flask, a pipette, a buret, and a graduated cylinder, and a 50mL beaker-- were for measuring water volume (mL). The tools used to determine the precision and accuracy were an electric scale, the provided 5 pieces of glassware, an extra beaker, a calculator, and 10 mL of H2O or water (distilled) per trial. The way to test the accuracy of a tool was to find how close the experimental volume of water in the given glassware was to the given theoretical volume, 10mL. Volume can be calculated with the formula mass/density = volume with the knowledge that water has a theoretical density of 0.997 g/mL under the lab conditions provided. To find
Separation of Liquids by Fractional Distillation and Analysis by Gas Chromatography Methods and Background This lab was exceptionally knowledgeable and important in order to understand how certain compounds can be separated based on their boiling points (Landrie, 43). This experiment in particular focuses on understanding the separation of 1:1 mixture of acetone and 1 propanol using the method of fractional distillation (Landrie, 43). In the previous experiment, we focused on understanding the same separation but in terms of simple distillation. If compared with the data shown below with the data in the previous experiment, overall, the fractional distillation showed better and more effective results (Landrie, 43). This experiment also provided better
After 2.5 mL of NaOH had been added to the solution, the color of the solution remained blue for an acceptable amount of time. It was imperative for the experiment to be as fats as possible when performing this procedure, since there were times at which samples had to be collected. After completing this process the content of the Erlenmeyer falsk were disposed of in the halogenated waste container, and the Erlenmeyer flask was cleaned and prepared for the next steps. This same process of treating with acetone and titrating the solution was repeated at the 20, 35, and 50 minute mark, and the amounts of NaOH added to had to be recorded as well. Table 1.A was constructed in order to represent the resultant amounts of NaOH that were used and their respective time that they were added, as well as the amounts of sample and acetone that were mixed, and Calculations 1.A shows the calculations used to find the concentrations of HCl at different times, which is needed for the calculation of the rate constant.
The first reason why we think is because when smelling it, it smelled like rubbing alcohol because it was very strong. The second reason is that the class average of 0.77g/ cm3 and my individual density of 0.80g/ cm3 are either the same or very close to the density of rubbing alcohol, which has a density of 0.80g/ cm3.(Mineral oil also has a density of 0.80g/cm, but it is odorless, not like liquid “A”.