Test Tube Mystery Lab Report

The primary goal of this laboratory is to correctly identify an unknown substance. To achieve this task, one may use various tests that reveal both chemical and physical properties of a substance. By comparing the results of a known substance and the unknown substance, one may eliminate alternative possibilities and more accurately predict the undisclosed compound. Furthermore, by performing these tests, data can be collected and verified regarding chemical and physical properties of the unknown. Understanding the chemical properties of a known substance aids one’s understanding of the unknown based on comparative analysis of the results of the tests.

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

One of the most important skills to have in the chemistry lab is the understanding of how chemicals will react. Knowing for example, how a chemical will react with a metal, is an excellent way of determining the amount of a particular metal in a deposit. This knowledge was used in this lab to determine the amount of copper in an unknown sample mixture. It is also known that the determination of the percent concentration of a certain solution, will directly effect the percent transmission and absorption of a solution, dependent upon its dilution. By first testing known concentrations of a solution, and plotting this information graphically, a line is formed

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

10. Ba (NO3)2, barium nitrate produces pale precipitate when put in reaction with sulfuric acid.

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).

Unknown 12 was proved to be Proteus vulgaris. This organism was a gram-negative rod growing in single. This organism, which grew on a TSA plate, was catalase positive. A drop of H2O2 was added on to the colony and it began to bubble. Therefore, the catalase enzyme was present and broke down the peroxides in to non-toxic forms H2O and O2.

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

Ba 2+ (aq) + 2 NO3- (aq) + Na+ (aq) + OH- (aq)  Ba(OH)2 (s) + Na+ (aq) + 2 NO3- (aq)

Most notably the reaction with heat and hot and cold liquid were interesting. Several attempts were made to obtain a smell from the reactions but none were found. When the samples were heated in water several of them had violent and/or sudden reactions.

In the first part of the experiment (identifying the chemical makeup of the unknown compound

b) Iron and Barium were present in unknown 3. Assigned unknown reacted with all 4 reactants and formed precipitate with 3 of them (Sodium carbonate, sodium hydroxide and Sulfuric acid). During the experiment it reacted very similarly to Iron (III) nitrate and Barium nitrate. For example, with it was tested against Ammonium Chloride, the color of the solution changed to a light green, very identically to Iron (III) nitrate and Ammonium Chloride. Besides, unknown 3 formed an orange brownish precipitate when it was tested with sodium carbonate. Iron (III) nitrate acted similarly. Moreover, unknown 3 reacted similar to Barium nitrate when it was tested against ammonium chloride and sulfuric acid. It did not form any precipitate with ammonium chloride but formed a very light white precipitate, which is identical to barium nitrate’s reaction against sulfuric acid. Therefore, the two present metal in unknown 3 are Iron and barium.

The purpose of this experiment was to classify unknown solids based on their type of chemical bonds by investigating their properties. By using data, Unknown 1 was classified as a metallic. This was because it appeared a shiny copper color, had a very high conductivity as a solid, had a high melting point, and was malleable. Unknown 2 was classified as a nonpolar covalent bond. This was because it had no conductivity as a solid and low conductivity in water.

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.