kwarny's blog

Doing fractional distillation is a more viable technique than straighforward distillation since less material is lost during the procedure. The distilled compounds would be more purified. The copper wire in the fractioning column acts to copy multiple distillations in one round of fractional distillation.

By doing fractional distillation of unknown 20, it was seen that unknown 20 had a higher boiling compound at about 79 degrees celcius and a lower boiling compound at about 56 degrees celcius. There is a 1:1 ratio of higher and lower boiling points. It can be determined that the lower boiling point compound is acetone because acetone's boiling point is 56 degrees celcius. It can be determined that the higher boiling point compound is 2-methyl-2-propanol. The therorectical boiling point for 2-methyl-2-propanol is 82 degrees celcius, which is about 3 degrees different from the experimental boiling point. The difference could be due to human error by heating the compound too quickly. The experimental results for this procedure are accurate because fractional distillation provides pure compounds, which are less likely to be lost during the process. 

When the vials were switched at the point of plateau, the original had barely any drops, however the original starting quantity was 4 mL. The second vial, which was removed at about 78 degrees celcius, was a mixture of acetone and 2-methyl-2-propanol. Vial 2 was replaced with Vial 3 containing 2-methyl-2-propanol. Vial 2 contained about 2 mL, Vial 3 had a little less than 2 mL, and Vial 1 had a few drops. Therefore, all three vials account for the original 4 mL of unknown 20 and emphasize the 1:1 ratio. 

In the biology field, mutualism is an interaction between two or more species in the same environment that benefit from one another. The species depend on each other for increased fitness and survival. On the UMass Amherst campus, the diverse wildlife provides opportunities for mutualism to occur within several species. Within the campus pond and its surroundings, resides year long habitats of numerous animals and plants.

I observed and photographed a mutualistic relationship between the campus pond and cattail plants that grow along the perimeter of the pond. Cattails appear as brown sausages on a yellow and brown stick attached to the upper half of the plant. The cattails grow well near the swampy area of the pond because they need a constant supply of water in its roots and exposure to sunlight to perform photosynthesis. Their roots in the water provide shelter for small fish underwater in ponds and the stems are a source of nesting materials for small animals to occupy.

A series of methods describes how the student took the images of the cattail and later how, another student from the class followed the instructions. The subsequent student’s aim was to replicate the procedures in hopes of obtaining the same results.  Critical factors were considered carefully, specifically time of day, weather, softwares, and equipment in order to perform the activity.

In this experiment, we explored how to identify a dog’s breed from extracting samples of the target dog as well as studying dog genomes by genotyping. A sample of the dog’s hair was obtained along with a buccal swab, which was then synthesized by numerous methods. We used methods of Polymerase chain reaction (PCR), lysis, sequencing and genotyping to analyze specific alleles linked to coat color such as MC1R, Agouti and TYRP1. These alleles have all shown correlation of coat color in dogs. Examination of the DNA markers in the dog’s genome made it possible to associate the results of sequencing to a specific coat color of the dog.

From the results of the melting point of the AE1, the identity of the unknown is 2-chlorobenzoic acid. The melting point for this compound was 143 degrees celsius and in the experiment protocol it was 142 degrees celsius. The less than two degree difference reaffirms that the unknown was a pure compound. The next step of calculating the percent recovery could have been caused by human error. During the extraction and filtration, it is possible that the solution did not become fully acidic by HCl before being left to cool, which would affect the product’s ability to recrystallize. In addition, this reasoning could also be applied to the OL1 recovery rate of 77.87%. The percentage could have been due to a lack of acidity or it could have been caused by the CaCl2 and NaHCO3 being unable to fully separate the compound from the solvent ether. The lack of acidity and insufficient separation of the compound would affect the amount of solute able to recrystallize and would further affect the recovery rate. The melting point of benzil was 95-96 degrees celsius, which is in the range of its known boiling point, therefore the compound is pure. The purified melting point reaffirms that the crystals were successfully purified because the melting point has less than a 2 degree celsius difference. The identity of compound AE1 is 2-chlorobenzoic acid and the identity of the compound in OL1 mixture is benzil.

The destination of the cattails at UMass Amherst was at the campus pond in the center of campus. To obtain the picture, a student visited the UMass pond during daylight hours and walked down the grassy hill that leads to the pond from North Pleasant Street. The part of the pond where the width is the smallest was approached. This area is past the gravel path that runs along the side of the pond. From about 15 feet away from the pond water border, picture ‘A’ (Figure 1) was taken from shoulder height of the student, with a camera, of a cluster of about 15 cattail plants. The cattail is shown in the center and the background shows the pond water and other tall, yellow, string-like grass that surrounds the cattail and then the edge of the pond makes up most of the foreground.

In this experiment, we explored the phenomenon of genetic complementation in yeast cells, saccharomyces cerevisiae, through mating. Within the procedure, we observed the yeasts’ entire life cycle- including the development of diploids and haploids, the process of gene complementation by mating and the impact of mutations due to specific external environments. In this experiment, exposure to UV radiation was used as a method to produce mutations in haploid yeast cells. The collected data include a simple cross between different mating yeast cells on a YED plate and then an MV plate through replication. In addition, the growth of meiosis and sporulation occur as we designed and performed a complementation test. The results further demonstrate the various genotypes and phenotypes of each parent and each offspring yeast cell.

From the results of the melting point of the AE1, the identity of the unknown is 2-chlorobenzoic acid. The melting point for this compound was 143 degrees celsius and in the experiment protocol it is 142 degrees celsius. The less than two degree difference reaffirms that it was a pure compound. The percent recovery could be caused by human error. During the extraction and filtration, the solution possibly did not become fully acidic by HCl before being left to cool, which would affect the product’s ability to recrystallize. This reasoning could also apply to the OL1 recovery rate of 77.87%. The percentage could be due to a lack of acidity or it could be caused by the CaCl2 and NaHCO3 being unable to fully separate the compound from the solvent ether. It would affect the amount of solute able to recrystallize and would further affect the recovery rate. The melting point of benzil was 95-96 degrees celsius, which is in the range, therefore the compound is pure. The purified melting point reaffirms that the crystals were successfully purified because the melting point has less than a 2 degree celsius difference. The identity of compound AE1 is 2-chlorobenzoic acid and the identity of the compound in OL1 mixture is benzil.

Solubility is the chemical property which refers to how much a solute will dissolve in the solvent. Polar compounds dissolve better in polar solvents, while non-polar compounds dissolve better in non-polar solvents. This is why the best solvent in the experiment for non-polar benzil is hexane because it is also non-polar. In addition, non-polar compounds have lower melting points since electronegativity is lower.

The first part of the experiment was spent finding the best solvent. It had to be insoluble at room temperature, soluble at boiling point, and crystalize in ice. Hexane was found to be the best solvent.

The next part of the lab was to recrystallize phthalic acid. It was dissolved in water, boiled, then placed in an ice bath to crystallize. Once the crystals formed, it was filtered to separate the impurities from the compound. Finally, recrystallization had to be performed for the unknown 6 and then calculate the melting point. The same procedure used to recrystallize and filter the phthalic acid was used for the unknown 6. The crystals were left to dry for five days and measured. The melting point of unknown 6 was 96 degrees celsius, which concluded to be benzil.

The observational differences between the original and the replicate resulted from various factors. The differences in the appearance of figure layout could be that different softwares were used to create it. The instructions may also not have been explicit enough to produce an exact replicate. The lighting differences in the photographs taken is most likely due to the fact that they were taken on different days and different times. Therefore, they did not have the brightness exposure depending on the weather. The different frames were likely due to different zooms because the exact zoom was not specified since the cameras weren’t required to be the same. Lastly, the arrows on panel ‘C’ are not the same because details on the type and size arrow was not specified

Ultrasounds are frequently used in the medical field to examine a specific region in the body’s inside. A few purposes include diagnosing pain, investigating infections, or examining a baby fetus in a woman's uterus. Furthermore, the procedure to perform an ultrasound is simple and requires minimal preparation, which makes it favorable to practice by nurses and doctors for their patients. In addition, ultrasounds are a safe and painless process that involves a probe and an application of ultrasound gel on the skin’s surface to inspect inside the body. High frequency sound waves are then transmitted through the probe and penetrate through the gel into the body. The machine then collects the sound waves and transforms them to create an image on the screen that can be analyzed. Not only can an image be produced but the transducer can additionally show the image in real-time and capture movement in the body’s internal organs such as blood flow. Lastly, the physical features can be seen such as flexibility of tissues. These analytical features allow ultrasound machines to be efficient for monitoring and diagnosing while simultaneously being safe to operate.