Recommended: Percent of yield lab report
=O groups present in the final product. This showed that my final product was not very pure and that there was a lot of contamination in the second part of the
As seen in table 1, the theoretical yield was .712 g of C_17 H_19 NO_3. The % yield of this experiment was 7.51 % of C_17 H_19 NO_3. . This low yield can be explained from a poor recrystallization technique combined with potential contamination. Throughout the experiment, the mixture changed color from green, orange, to yellowish lime, and eventually clear.
Thus, using the theoretical yield (Equation 3) and the weights of crude and pure product discovered, the percent yield of crude product (Equation 4), the percent yield of pure product (Equation 5), as well as the percent recovery (Equation 6) were determined. Moles of the Reactants: Moles of bromobenzene = weight of bromobenzene (g)molecular weight (g/mol) = 1.218 g157.01 g/mol = 0.0078 mol Moles of magnesium = weight of magnesium (g)molecular weight (g/mol) = 0.153 g24.3 g/mol = 0.0063
This low percent recovery is because some of the solutions spilled onto the table, losing a lot of the precipitate. The recovered ethyl-4-aminobenzoate’s boiling point was within the accepted range of 85C; meaning, the amount recovered was pure. The % recovery for the benzoic acid was 5.33%. This low percent recovery could be due to the fact that instead of adding NaCl to increase the precipitate amount, the salting out effect, more of the HCl was used. This caused the precipitate amount to increase slightly but not as much as it could’ve if the salting out effect was used.
(150.22g/mol)(3.5 x 10^-3 mol of nucleophile) = 0.525 g Actual yield = 0.441 g, Percent Yield = (0.441g/0.525g) x 100% = 84% 10. Percent recovery from recrystallization = (0.172g/0.441g) x 100% = 38% 11.
Secondly, the test tubes were not cleaned out. If there was residue from other chemicals on the test tube there could be an error in the reaction. Cleaning out the test tube before starting lab could prevent this. Finally, residue on gloves could have got into the solution. This could have caused an error in the reaction.
3. In this experiment, the percent yield was 90%. This number implies that there was little error in this experiment. However, this result could have been caused by certain external factors.
1. What was your theoretical yield and your percent yield? Theoretical yield: 3.9151 g Percent yield: 79.30% 2. An accurate percent yield must be below 100% Why?
The percent yield was 22.33%. In most cases, that means that a lot of possible product was lost. However, in this case, that was not true. When Benzaldehyde reacted with the Wittig reagent, it produced two products: E-Stilbene and Z-Stilbene. The Z product was a liquid, while the E product was a solid.
The purpose of this lab was to determine the percent water in magnesium sulfate heptahydrate, or Epsom salt. The experimental percent water is determined to be 42.06% in both trials, making the average also 42.06%. To determine this percent water a heating and cooling procedure was used. First, the vials were cleaned of impurities using the lab oven and were not touched after this point.
If only one reactant is increased, then the chemical reaction will only produce a certain amount of products after the limiting reagent is used up, and in this experiment, the most mass the reaction could produce was 0.4 grams. Although we kept adding calcium chloride, not adding sodium hydroxide in the same proportions will not yield more product, which is the main goal in conducting this lab. We should have seen a plateau at 0.4 grams to show that the limiting reagent inhibited further Ca(OH)2 production, but we made several mistakes in our experiment, which made the data unusable to conclude. Once again, the data is polluted, so these number are not accurate, but it is the data our group has to work with. The theoretical yield should have been more than the actual yield, and the percentages should have been less than 100.
The percent recovery was measured by dividing the amount from the second extraction on the total amount extracted multiple by 100. By using extraction solvent of 100 % methanol, the percent recovery was between 1-5 %, with mean value 3.72 %. That is considered slightly higher percentage when compared with the reported from Esteve et al. With increasing the dilution of Methanol, a slight increase reported in the percent recovery mean value between 12.17 – 16.33 %. PBS solution can be used for extraction of cocaine, although it has very high recovery percent of an average of 20.91%.
The melting point range for the crude product was 113-115.3℃. the melting point range for the purified product was also 113-116℃. This melting point range was almost perfect to that of the theoretical melting point which is 113-115℃ proving that the product was in fact created. When looking at the percent yield of the crude acetanilide, there was an 81% yield which was a very good yield because the average percent yield is between 80-90%. The percent recovery of the acetanilide was 88% which is also very good because much of the product was recovered meaning that the product was in fact
The data used in this experiment is the average of all the plants height, and does not count the length of the roots. This is because the averages will provide a more even set of data because not all plants are exactly the same and due to genetic variation some may grow higher or shorter than others. The data being analysed is the height it grew from when the hormones was placed on the plant (day 4), this is to ensure that if a plant grew taller or shorter than the others from day 0 till day 4 it would still be accurate when comparing to the other tests. Primary Data: In this experiment the average growth ranges from 0.7cm to 10.2cm in six days from when the hormones were placed on the plants for dicots, and 5.9cm to 10.4cm from when the hormones were placed on the plants for monocots.
Pre- lab preparation To perform this investigation, a number of the solutions were needed to be prepared in advance. The following is the preparation process - Preparing the stock solution-The stock solution of Salicylic acid needed to be prepared well in advance before the experiment began. To do so, 1.73g of Salicylic Acid was weighed using the weighing balance. After Salicylic acid was weighed, it was transferred to a standard flask of 100cm3 and, 100cm3 of pure Ethanol (C2H5OH), was poured into the standard flask that contained the Salicylic acid.
