An unknown salt sample was placed at the lab station and the sample number was recorded. Two uncontaminated and dry crucibles were previously taken out of a 110oC oven 20 minutes prior to the lab section by the TA, to cool. An analytical balance was used to accurately measure the mass different of a 0.1000g to 0.1500g sample of the unknown salt. The masses of the unknown salt sample number #338 was both weighed by the difference into a 200ml beaker. The mass of the sample salt obtained by the author was 0.1054g and the amount obtained by the author’s partner was 0.1104g respectively. The estimated volume of 0.1 M AgNO3 that will be needed for the precipitate volume will be calculated.To make sure that all chloride are precipitated, 5 ml of O.1 M AgNO3 was added to the calculated approximate volume to which another 1ml of dilute (6M) HNO3 and a 100 ml of distilled water were also added. …show more content…
Stirring the mixture gently till is almost at boiling point; drops of silver nitrated were added to check if the mixture was entirely precipitated. After through precipitation, the mixture was placed in drawer to cool down. In the meantime, the sinister glass crucible was weighed on the balance. After the mixture put in the drawer has cooled, the vacuum filtration apparatus was put together and the supernatant liquid was poured into the glass filter leaving the precipitate in the beaker. This process was done again when more amount of 0.01M HNO3 was added to thoroughly filter and transfer the precipitate in the crucible. The flask was cleaned after detaching from the crucible and then reconnected to the crucible to be filtered out one more time with 0.01M HNO3. This time, the aliquot of HNO3 was put in a test tube and given to the TA to test for no turbidity. After the TA’s approval, the apparatus was reconnected and three 5ml portions of acetone washed the
As a group, we obtained our salt mixture of calcium chloride and potassium oxalate, and weighed the mixture. We were able to make an aqueous solution from the mixture and distilled water. We boiled and filtered off the solution, leaving the precipitate. Once the precipitate was dried overnight, it was weighed and the mass was measured. Then we calculated the moles of the precipitate.
In reference to the analysis of anions, Table 1 shows that a precipitate was formed when our unknown was combined with HNO3 and AgNO3, thus indicating the presence of a chloride ion. Because our unknown did not form a precipitate due to HCl and BaCl2, separate, effervesce, or smell, we concluded that neither sulfate, nitrate, carbonate nor
To begin the procedure of the gravimetric analysis of chloride, 0.501g of Amine (C8H9NO) was weighed on an analytical balance and added to a 10mL volumetric flask. At this point 5mL of deionized water was added to dissolve the Amine. Then 5mL of 1 M AgNO3, which was already combined with 4 M HNO3, is added to the 10mL volumetric flask and stirred. To collect the AgCl precipitate,
My unknown organism #6 is Morganella morganii, which is a gram-negative bacillus rods commonly found in the environment and also in the intestinal tracts of humans, mammals, and reptiles as a normal flora. (3, 5) This bacterium Morganella morganii, was first discovered in the 1906 by a British bacteriologist named H. de R. Morgan. (2) Despite its wide distribution, it is an uncommon cause of community-acquired infection and is most often encountered inpostoperative and other nosocomial settings. (2, 3) Morganella morganii infections respond well to appropriate antibiotic therapy; however, its
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).
Bacteria are ubiquitous; they can be found on the skin, in the soil, and inside the body. Because of the very nature of this ubiquity, it is important to be able to determine between different strains of bacteria. An example of this is determining the causative agent for a disease so that the patient will be treated with the appropriate antibiotics. It may be important to determine the bacteria in a certain region, because like with enteric bacteria, it is normal to find them in the digestive tract as they are in a symbiotic relationship with our bodies in this area; however, they also cause opportunistic infections in places outside of the digestive tract to our detriment, such as with a urinary tract infection. Some strains of bacteria are common to nosocomial infections, and identifying these bacteria as such helps create the guidelines for healthcare workers in antiseptic technique. All of the morphology and characteristics of each strain of bacteria help us to better understand the role of bacteria in the body as well as helps us understand how they can cause illness, and what treatment regimen to set in place. In lab this semester, a sample of unknown
The purpose of this experiment was to find the amount and percent of water in a hydrated salt. Hydrated salt contains water molecules chemically bound to it while anhydrous salt is a substance that fire can readily remove the water molecules. Using the gravimetric analysis method, the sample salt was measured, heated, and was measured again after cooled down to room temperature; this procedure allowed the weight of water lost in the salt to be obtained. After two trials, the water in the salt was determined to have an average percent water of -35.04%. The null hypothesis, the heat will not affect the amount of water lost, was rejected ,however, the alternative hypothesis, the heat will allow for there to be water lost, was not supported.
For example, silver nitrate formed a white precipitate when it was tested with ammonium chloride. In contrast, unknown 3 did not formed any precipitate with ammonium chloride. Ammonium chloride change the color of unknown 3 to a light green while the solution of silver nitrate and ammonium chloride was cloudy white solution. Likewise, the metal in unknown 3 could have been Calcium neither. Data and observation shows that calcium nitrate whether formed a white precipitate or did not react at all while unknown 3 formed an orange precipitate. Therefore, silver and calcium are not the two metal present in unknown
Triple Sugar Iron Agar test, there was a gas production seen in the media. The media was yellow slant and yellow butt indicating glucose, lactose and/or sucrose fermentation with acid accumulation in slant and butt. For sulfur reduction, it was negative since it did not turn black in color indicating no sulfur was reduced.
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.
The goal of the experiment was to identify Unknown 33A and 33B. Unknown 33A was a white, crystalline solid that had a sweet cherry smell and Unknown 33B was a beige, yellowish color liquid that was translucent and had a viscosity similar to water. Also, the liquid was homogenous and smelled sour, similar to mildew.
Aim: To classify unknown substances according to their structure type and to observe how the structure of materials affects their uses.
An unknown was given to our group from the professor. The unknown was in nutrient broth, the group received unknown number 3. And the task was to identify the unknown and try to make an educated guess, and identify the unknown #3.
An ice bath was prepared in a large beaker and a small cotton ball was obtained. 0.5 g of acetanilide, 0.9 g of NaBr, 3mL of ethanol and 2.5 mL acetic acid was measured and gathered into 50mL beakers. In a fume hood, the measured amounts of acetanilide, NaBr, ethanol and acetic acid were mixed in a 25mL Erlenmeyer flask with a stir bar. The flask was plugged with the cotton ball and placed in an ice bath on top of a stir plate. The stir feature was turned on a medium speed. 7mL of bleach was obtained and was slowly added to the stirring flask in the ice bath. Once all the bleach was added, stirring continued for another 2 minutes and then the flask was removed from the ice bath and left to warm up to room temperature. 0.8mL of saturated sodium thiosulfate solution and 0.5mL of NaOH solution were collected in small beakers. The two solutions were added to the flask at room temperature. The flask was gently stirred. Vacuum filtration was used to remove the crude product. The product was weighed and a melting point was taken. The crude product was placed into a clean 25mL Erlenmeyer flask. A large beaker with 50/50 ethanol/water
The black precipitate was allowed to settle and then the supernatant, the clear liquid that lies above a precipitate, was decanted, or poured carefully off. Then, 200 mL of hot distilled water was added and the precipitate was allowed to settle to repeat the decanting process again.