Okay, I have some confusion on a lab question for chemistry.
The question was if you were preforming a microscale extraction of a 0.2 g of benzoic acid/fluorenone mixture (About 6 mL of dichloromethane and 2 mL of NaOH were added through out this experiment up until the final steps of heating to the evaporation of flurenone and filtration of the acid) and the recovered mass of the benzoic acid was determined to be .05 grams, what would the approximate mass recovered of the fluorenone be under normal lab conditions?
Our class has never preformed this lab before, but I know percent recovery is mass recovered divided by mass of original sample x 100. So the acid % recovery would be around 28% by that math. But the other I have no idea really. I know a % recovery of over 100% or near 100% is not possible/realistic. So would the mass recovered of the fluorenone be something around .1 g I guess since the acid mass was so small compared to the sample weight making the overall recovery 76% or is that still too low?
If you are looking for percent recovery benzoic acid as a percent of the original sample it is (0.05/0.2)*100 = 25% but that may not be percent recovery of the benzoic acid since you don't know how much benzoic acid was in the sample initially. If you can assume the fluorenone was the rest of it then it is 75% BUT I doubt that assumption is valid. If you have a table showing solubility benzoic acid and fluorenone in the solvents used and at the temperatures used we might be able to do a better job of estimation.
To find the approximate mass recovered of the fluorenone, we can use the concept of percent recovery.
First, let's calculate the percent recovery of the benzoic acid, which you correctly calculated as approximately 28%. This means that 28% of the original mass of benzoic acid was recovered.
Now, assuming that the recovery of the fluorenone is also around 28%, we can calculate the mass recovered. However, since we don't know the exact mass of the original sample, we cannot determine the exact mass recovered.
To estimate the mass of the original sample, we can use the percent recovery of the benzoic acid. If 28% of the benzoic acid was recovered, then it implies that 72% of the benzoic acid was lost or reacted with other substances. Assuming the overall reaction stoichiometry did not change, we can assume that the same percentage of the fluorenone was lost as well.
Since the total percent recovery is 100%, we can subtract the benzoic acid percent recovery from 100% to estimate the percent recovery of the fluorenone: 100% - 28% = 72%
Now, let's use the estimated percent recovery of the fluorenone (72%) to calculate the approximate mass recovered. We can use the formula:
Mass recovered = (Percent recovery / 100) × Mass of the original sample
Substituting in the values:
Mass recovered = (72 / 100) × Mass of the original sample
Since we don't know the exact mass of the original sample, we cannot determine the exact mass recovered. However, we can estimate it based on the percent recovery. If the mass of the recovered benzoic acid was 0.05 grams, the mass recovered of the fluorenone would be:
Approximate mass recovered of fluorenone = (72 / 100) × Mass of the original sample
Assuming the mass of the original sample was 0.2 grams (as given in the question), we can substitute the value to get:
Approximate mass recovered of fluorenone = (72 / 100) × 0.2 grams
= 0.144 grams
Therefore, under normal lab conditions, the approximate mass recovered of the fluorenone would be approximately 0.144 grams. Keep in mind that this calculation is based on assumptions and estimations, so the actual values may vary.