Lab Mistakes

The mole is a convenient unit for analyzing chemical reactions. Avogadro’s number is equal to the mole. The mass of a mole of any compound or element is the mass in grams that corresponds to the molecular formula, also known as the atomic mass. In this experiment, you will observe the reaction of iron nails with a solution of copper (II) chloride and determine the number of moles involved in the reaction. You will determine the number of moles of copper produced in the reaction of iron and copper (II) chloride, determine the number of moles of iron used up in the reaction of iron and copper (II) chloride, determine the ratio of moles of iron to moles of copper, and determine the number of atoms and formula units involved in

The purpose of this lab was to identify unknown bacteria cultures using various differential tests, and my unknown bacteria is #17. The identification of these unknown cultures was accomplished by separating and differentiating possible bacteria based on specific biochemical characteristics. Whether the tests performed identified specific enzymatic reactions or metabolic pathways, each was used in a way to help recognize those specifics and identify the unknown cultures. The differential tests used to identify the unknown cultures were Gram stain, Catalase, Mannitol Salt Agar (MSA), Blood Agar, Novobiocin, Coagulase, and DNAse (Alachi, 2007).

An unknown sample is identified using the relationship between the mass of the product and mass of the reactant in a balanced chemical equation using the involved species molar mass.

I’ve had the opportunity to view several research labs over the course of the UNMC High School Alliance school year, but so far visiting Dr. Conda Sheridan’s lab has been the most interesting so far. We got to see several of the projects that they were working on, and what was different from some of the other labs that we have visited is that you could actually see the changes happen in the solutions as the reactions took place. For example, Dr. Conda Sheridan showed us how he would isolate specific parts of a liquid compound he wanted by adding chloroform as a natural soluble. We were able to see as the liquids separated before he drained the unnecessary portions and then repeated the process. It was interesting to see some of the ways they

Data were collected in September and November 2017 at the Elk Valley Preserve and Field Station in Banner Elk, NC. The preserve is located at 36°10'17.2"N 81°54'45.9"W, in Avery County in western North Carolina. The area is a mixed deciduous forest at an altitude of 1,127 m above sea level. Data were collected in early fall, during which temperatures average around 10-18 degrees Celsius. Summers in Banner Elk are typically mild, with temperatures averaging 21 degrees Celsius, and winters are cold and snowy, averaging near zero degrees Celsius. During the months of September and November there is an overall average precipitation of 12-25cm.

Our second attempt today was successful and better today than the first attempt because we were able to prove the law of conservation of mass on the second try. During the second attempt, we were already aware of the mistakes we executed. Therefore, this helped us to avoid repeating the same mistakes and draft another procedure while taking in consideration the first attempt of experiment we had performed previously. Our procedure were also more structured and organized since we already had an idea of how to conserve the gas, which is carbon dioxide, that accumulated due to the chemical reaction brought by combining baking soda and vinegar. After watching the video, we realized that our vital mistake during the first attempt was failing

There were four different experiments to conduct, which were observed in order to obtain data regarding the reaction and outcome. For each reaction, a test tube is needed and the desired amounts of each substance to be used. A Bunsen burner, tong, and droppers were also needed to perform the experiments. Proper standard lab attire is needed to perform the lab, along with gloves, an apron, and protective goggles. This is to avoid any harm for each student.

Studies show that unwashed or lightly rinsed vegetables can harbor pathogenic bacteria and have been implicated in numerous foodborne infections. The objective of this experiment was to obtain a quantitative viable plate count of enteric bacteria present in a sample of broccoli sprout water. To enumerate the number of bacterial colonies present in the sample, we performed serial dilutions of broccoli water spread onto MacConkey Agar plates. MacConkey Agar is a selective and differential media. It is used to select enteric bacteria and differentiate lactose-fermenters from non-lactose fermenters. Utilizing this process illustrated the potential amount of foodborne illness causing bacteria present on foods, specifically fresh broccoli

The first possible source of experimental error in this experiment was the fact that our lab setup was not working properly since it was giving the lab group different data which lead to a higher than usual percent difference. This may hvae been caused by faulty lab equipment. The second source could've came from the PASCO since our data was incorrect depsite having a correct set-up. The third source may have been a faulty curcuit board since the data was also incorrect. Every source could have been responsible for the high percent difference.

Three sources of error that might have led to the systematic error during the lab include: lack of insulation, lack of even heating, and loss of heat to the environment. First, in my experiment I had to set the sample foods aflame in a coffee tin, which would heat the water inside the soda can. There was a large amount of heat that escaped through the top of the soda can, which made the water have a smaller temperature change. Secondly, there was incomplete burning of food in my experiment. The marshmallows did not burn; instead they caramelized on the outside, so not all the energy contained was released. Incomplete burning also occurred with the animal crackers. Lastly, my inefficiency was caused by heat loss to the environment. When trying

The petroleum lab and environmental reflect the major focus of the lab well. The abstract concisely communicates the purpose of the lab, the approach, the results, and the significances of the findings. The electrical lab doesn’t have an abstract but sometimes instructors do not require an abstract section. The environmental lab does a better job at writing the abstract because it’s shorter and more direct to the point, therefore easier to understand.

Audit Recommendation #3 --- (8th STB) direct watercraft units to train for their mission-essential tasks by having vessel masters:

In order to investigate the expression of miR-365b-3p in normal cells and lung cancer cells, we used real-time PCR to measure the expression of miR-365b-3p in various cells. Results showed that the expression of miR-365b-3p was significantly lower in lung cancer cells compared with that in normal cells (Figure 1). After transfection, the expression of miR-365b-3p in COLO 668 cell line was successfully upregulated by miR-365b-3p mimic and inhibited by miR-365b-3p inhibitor (Figure 2A). Cell viability assay showed that miR-365b-3p suppressed cell viability while miR-365b-3p inhibitor promoted cell proliferation (Figure 2B). Furtherly,

Management will evaluate the significance of nonconforming work and notify clients in writing within three days of the investigative conclusion. Management will document to the client how the reported test results were affected. The laboratory Corrective Action Report will indicate the name of laboratory personnel who notified the client(s).

A potential source of error can be the amount of fire that is used on the paper (soaking in the chemical). As there was no specific time that the fire remained on the paper (from the lighter), the fire could have affected the intensity of the initial spark on the paper. Resulting in a longer time period that the fire was active. This would then change the data that was gathered and it would affect how powerful each retardant seems. Another source of error can be the amount of water and dry chemicals that were used. As the same graduated cylinder was used for the measuring and pouring of the deionized water, the 2nd-4th trials may have had an extra amount of water as there were drops left over in the graduated cylinder. This can also a reason for the dry chemicals. As the