Calorimetry Percent Yield

The percent yield for trial one is 83.4% and for trial two is 84.9%. These results show the experiment was successes. One major factor that will affect the mass of silver that produces is the crucible was not heated enough at the beginning of the lab. There will be debris left in the crucible and some water molecules store in the crucible caused by a humid environment. This will increase the mass of oxygen production. Or during the measurement of the silver oxide, there will be ±0.001 grams of error. All those potential mistakes could affect the accuracy of the results. These uncertainties could increase by heating the crucible for a longer period. Clean the crucible and its lid before the lab, to make sure there are not any dust left in it. At the same time increase the time for heating the empty crucible and its lid. Also, the balance that with 0.0001 precision could be used for the future lab. However, the percent yield for these two trial are precise and the lab was

In this experiment, the precision of percent by mass of sodium carbonate was decent. It seemed to be consistent, although we seemed to have an outlier in our fifth trial. I believe this was due to human error of adding too much vinegar to this graduated cylinder. The accuracy of our results was decent in comparison to the rest of the class’s data, but our results were on the higher end compared to the averages of the class data, though not too high to be considered

The GC data for the product produced graph with a signal level out-of-range in peak. This gave a retention time 2.952 minutes. This would not indicate any of the possible ester products. However, after appropriate dilution, a retention time of 1.753 minutes was obtained. This retention time indicates that the ester product was ethyl benzoate.

The possible reasons for this discrepancy were discussed as the plausible mistakes committed in the procedure, such as allowing the solution to excessively cool, as well as the possibility of having used faulty or contaminated reagents and components. In general, in order to improve the results of future experiments, as well as to have potentially improved these results, a more diligent and strict manner of performing these experiments is necessary, as well as ensuring the purity and condition of any reagents used and to ensure that no objects such as glassware are compromised. Considering this information, the experiment must be considered a failure, although the purity of the small yield could be considered pure, the yield’s sheer lack of size is evidence of the fact that the reaction did not reach completion, whether it be because of a low temperature or a lack of purity in components. Therefore, it must be regretfully reported that the objective of the experiment was not

Strontium nitrate, the limiting reagent, was poured into the copper(II) sulphate solution, the excess reagent, rather than the other way around. This is a minor systemic error, because even if some of the strontium nitrate remained in its initial beaker, the beaker was thoroughly rinsed out multiple times. The error causes the final mass of the filter paper and precipitate to be slightly decreased, as not all of strontium nitrate reacts with the copper(II) sulfate. This can explain why the percent yield in 92.2%.

Unreacted benzoate ions are most likely the cause of the low percent recovery. If not enough HCl was added, not all of the benzoate ions would be protonated. TLC tests on benzoate ions and the filtrate could be performed. If the percent recovery is due to product dissolving, a TLC test on the product and filtrate could be performed.

Use approximately 2 feet of aluminum foil to wrap around the burner stand and beaker to minimize heat loss.

The percentage of the product being recovered is more than 50% which is 59%. The Percentage yield obtained is not 100% as what we expected, this might be due to the spillage of the benzoic acids when it was being measured or transferred and the benzoic acid was not weighed properly. It might also be caused by the errors when the benzoic acids solution was not filtered properly and they might have trapped in the filter paper.

Varying concentrations of chemically-manufactured acetone solution were used in this experiment, which also acted as the control for the detection of acetone. Measurement was made using the UV-Vis spectrophotometer.

An ester was synthesized during an organic reaction and identified by IR spectroscopy and boiling point. Acetic acid was added to 4-methyl-2-pentanol, which was catalyzed by sulfuric acid. This produced the desired ester and water. After the ester was isolated a percent yield of 55.1% was calculated from the 0.872 g of ester recovered. This quantitative error was most likely due to product getting stuck in the apparatus. The boiling point of the ester was 143° C, only one degree off from the theoretical boiling point of the ester 1,3-dimethylbutyl, 144 ° C. The values of the

The product attained was a white, dry solid. The small amount of product lost during the second recrystallization was most likely do to impurities, which were filtered away with the methanol. Impurities that contributed to the low percent yield could be due to side reactions such as methyl o-nitrobenzoate and methyl p-nitrobenzoate. Although the percent yield attained was low, the product attained was fairly pure due to similarity in melting point and IR spectrum compared to standardly accepted values for methyl m-nitrobenzoate.

My data seems to match up with the class data, there is very little difference in the percent yield in the other espresso tests, and the one that I had done, other than one that had a high yield of 15.23% of crude caffeine, which could have been an error in the experiment. The class average of the crude caffeine from espresso came out much higher than expected results, but this is probably because of the one result that had a very high recovery

The purpose of this experiment is to investigate how the caloric energy in food varies in different foods and the correlation between high fat foods and calories using a homemade calorimeter.

The percentage yield of 64.07% is a moderate yield and was better than expected considering the problems that were encounters at the start of the experiment. The yield percentage could have been better if there was no loss of product when transferring the product for the filter to the watch glass. A small error was also made by not weighing the watch glass before the Acetaminophen had been transferred to it for drying. This meant that one friend the Acetaminophen had to then be transferred again into a weighed watch glass, this is another example of where product could have been lost thus affecting the yield percentage.

As seen in Figure 3, the percent yield exceeded one-hundred, indicating a source of error. When weighing, the methyl acrylate