Multistep Lab

The original 1.0 gram of the 50/50 mixture of the benzoic acid and benzil contain 0.5 gram of benzil. Thus, from 0.5 gram of benzil, only 0.266 gram of benzil was collected. The percent recovery of benzil was calculated to be 53.2%. This low percent recovery could be due to filtration errors. Some amount of benzil remained on the filtration paper that contained the MgSO4. In order for determining the purity of the

In this lab, liquid-liquid extraction was performed to isolate a mixture of benzocaine and benzoic acid. 2.0107 grams of the mixture was first weighed out for the trials. When HCl was added to the mixture for the first acid extraction of benzocaine, an emulsion formed during inversion and venting that prevented a defined separation of the two layers. 8 mL of water was therefore added before continuing the extraction. The addition of NaOH then turned the top aqueous layer basic, indicated by the pH strips that turned blue when tested. A vacuum filtration isolated 0.29 grams of benzocaine and a MelTemp apparatus measured the crystal’s melting point ranges to be 85.1C-87.4C. For the base extraction of benzoic acid, the aqueous layers were retrieved

The vial was removed from the heat and cooled to room temperature. The spin vane was rinsed with 2-3 drops of warm water over the conical vial. The vial was cooled to room temperature then placed in an ice bath for 15 minutes. The liquid was decanted from the mixture and the resulting crystals were dried on filter paper. The crystals were then placed on a watch glass for further drying. The crystals were weighed and a small sample was placed into a capillary tube for melting point determination.

1.5mL of phosphoric acid including 3-4 boiling chips were also added to the 25mL flask. The short path distillation apparatus was set up as shown in Figure 1. A heating mantle was used to heat up the 25mL flask. The solution was distilled to the receiving flask until a small amount of liquid remained in the initial RBF flask. At this point the presence of thick grey smoke pulling over into the entire apparatus was observed. The apparatus was then left to cool down. Through the use of pasture pipette, the aqueous layer from the distilled solution was drawn out. Sodium carbonate was then added to the remaining organic solution in order to check the pH and to verify the basicity of the solution. The aqueous layer was again drawn out from the solution. Next, 0.5g of sodium sulfate was added to the remaining organic layer and was swirled until the liquid appeared to be dry and clear. The alkenes were transferred into a clean 10mL flaks using another clean pasture pipe. The apparatus from the first distillation was rinsed off with

Using the air temperature, dewpoint and wind field in the images below, how many different airmasses are located in Oklahoma?

1A. Matter is a type of vaporation of a liquid that appears from the surface of a liquid into a gassy period which is not soaked with the evaporating essence. Another type of vaporation is boiling, which is represented by bubbles of wet vapor in the liquid point.

The percentage yield calculation reveals that approximately 90% of benzoic acid as white precipitate were recovered from the reaction. There were a number of factors which might have contributed to the 10% deficiency in the final yield. It needs to be mentioned though that a percentage yield of less than 100% is achieved because the drying of the solid mass after vacuum filtration was sufficient to give a practical number. During measurements of mass of benzoate and benzoic acid when it’s formed, there were obvious human errors involved. Some benzoates were lost while transferring to the conical reaction vial from the watch glasses, and further loss of the product benzoic acid might have taken place when the solution mixture was tipped on the Hirsh funnel. We couldn’t determine if the reaction was complete or not, so we might not have had all the salt converted 4. The solution might not have sufficiently and gradually cooled though every effort was made for that, hence there could be lack of benzoic acid crystals forming.

Well, Don't understand why we need to advise LabCorp to bill their visit to SFL .I think this is something that SFL needs to takecare and get in touch with them.Remember that we provide to SFL the billing contact person few months ago b/c in the past we have the same issue. If you see the list that Chelsea FWD to me the majority of her advise is for LabCorp.

After the initial mixture has refluxed, 9.11 grams of benzophenone was dissolved in 100 mL of anhydrous ether in a beaker and was then transferred into the separatory on the reflux apparatus. This solution was then added to the Grignard reagent at a drop wise rate while stirring. After the benzophenone was added, the mixture was then refluxed for 15 minutes on a heating mantle.

Paragraph #2 – Further elaborate on why you should be considered for a postdoc in this particular laboratory. Customize your letter and outline how your skills match or complement those of the Principal Investigator. Use the keywords that you identified in the job description or from the publications from the Principal Investigator’s laboratory. Failure to be specific to that Principal Investigator’s work makes you look uninterested and lack initiative -- who would want to hire someone like that? Also identify areas that you want to learn from the Principal Investigator’s laboratory.

Dissolve crude product of previous crystalinization in a clean 125 mL Erlenmeyer flask with ethyl acetate (2-3 mL). Gently heat the solution on a hot plate to dissolve the reagents and then allow the solution to cool down at room temperature. At this point crystals should form, if not add petroleum ether to the solution. Place the flask with the solution on an ice bath until crystallization is complete. Once again, set up the vacuum filtration that was used to collect crude crystal product and vacuum dry the crystals for 10 minutes. Perform the ferric chloride test by setting up four test tubes with salicylic acid, products of crystalinization, products of re-crystalinization and distilled water respectively in order to detect the presence of phenol. Finally, after placing the products of re-crystalinization in the oven for 5-10 min record its mass and its melting point.

The purpose of this experiment was to synthesize an ester and to examine the reactions of an acid chloride with ammonia and water. This experiment was done over a period of two weeks. During the first week, the synthesis of methyl benzoate was performed, as well as the hydrolysis and ammonolysis of benzoyl chloride. For the second week, the distillation of the methyl benzoate was performed and the melting point for the products of hydrolysis and ammonolysis was obtained.

Prior to doing the lab investigation, the students will sketch graphs predicting what the force and spring stretch relationship will look like. Their graphs will demonstrate that the students that their data will need to support or reject their initial predictions; more importantly, the students will get an idea of what data to gather to support or to change their predictions. Once the students have finished plotting their data, they will share their findings with the class by explaining the relationship that their data indicates. To ensure that all students understand the importance of the learning targets, they will explain to one another why it is important to become skilled in data collection and in data analysis; they will also get to

This lab is to test the success of variable practice. The idea of variable practice is that a learner will be better at a set skill if he/she learns to do it multiple ways; over doing it only one way. To test this theory, two groups of test subject will be set up. One group will be doing variable practice and the other will be doing constant practice.

Recrystallization was done to remove impurities from the sample. The percent recovery of benzoic acid during recrystallization is 23.02%. The difference between the pure and impure samples was observed by comparison of melting points. It was found that impure sample had a lower and wider melting point range of 120.1-122.2 (C). The pure sample melting point range was 121.3-122.5 (C). These ranges helped determine purity by comparing the known melting point of pure benzoic acid.