Experimental Procedure Identifying the Unknown We performed three tests on our compound to definitively identify it. First we combined 5 g of our unknown compound with 10 mL of distilled water and measured the pH change in the water to test its solubility. Then, to try to identify the cation present in our compound and narrow down the possibilities, we held a sample over a flame and watched for color change. We performed an acid test where we applied a few drops of HCl and watched for a bubbling reaction, to test for the presence of carbonate. Confirming the Identity Now that the test were concluded we made a hypothesis as to the identity of our unknown compound. To verify the unknown compound’s identity, we performed the conductivity test, and the previously mentioned tests on a sample of the hypothesised compound and compared the results. Synthesizing the Compound After we had confirmed the identity of the unknown compound, we attempted to synthesize an exact copy of it. Therefore, we added 1.11g of CaCl₂ and 1.06g of NaCO₃ to a beaker filled with 70mL of distilled water. To separate the precipitate from the aqueous solution, we vacuum filtrated the contents of the beaker. Once we determined that the …show more content…
The flame test produced inconclusive results because we were unable to determine whether the flame produced a faint orange tint or no color. Next we tested the pH change that the compound caused in water to determine its solubility. Our known compound did not dissociate or dissolve in water, instead it formed a white colored precipitate, therefore that eliminated a lot of the choices from the unknown compound list. In addition, when we performed the acid test, the unknown compound bubble which revealed it must be a carbonate. The previous test reveal it did not dissociate in water, therefore the only option from the list it could be was
Discussion 1. Zn0 (s)+ Cu2+S6+O42-(aq) →Cu0(s) + Zn2+S6+O42-(aq) Zn0(s) → Zn2+(aq) + 2e- Cu2+(aq) + 2e- → Cu0(s) Zn0(s) + Cu2+(aq) → Zn2+(aq) + Cu0(s) Oxidant (oxidizing agent) is the element which reduces in experiment.
The goal of this experiment is to find out what is the identity of the unknown hydrate? To answer this question first, we should know what a hydrate, and how to identify a hydrate using the law of constant proportions. A hydrate is a pure substance because it contains water molecules embedded in its crystal structure that does not vary. By heating the unknown hydrate, we can calculate the mass of the hydrated, and the percentage of water in the hydrate.
Identification of bacteria within Unknown Culture #21 In this experiment, an unknown culture of two different types of bacteria was assigned to each person, a number of tests were performed to isolate and identify these bacterial cells. Based on knowledge from the previous experiments completed in lab, a basic understanding of each type of bacteria was used to create a flow chart that would aid the process of identifying the unknown bacteria within the culture. A gram stain that is performed initially will narrow down the types of tests certain bacteria will and will not respond to. In addition to the gram stain, some of the tests that were used include, a catalase test, an Eosin methylene blue (EMB) agar test, a bile esculin test, and a 6.5% sodium chloride (NaCl) test.
The purpose of sludge was the following: To use lab skills learned throughout the year to separate and identify each pure substance in the original mixture. The sludge that was given to the group had the name of Ramos. The mixture of Ramos was a dark, orange, murky liquid that had a few objects floating around in it, such as (or hypothesized as) orange blocks, and tiny ‘metal’ rods. The mixture also had a substance that looked like, and appeared to be, sand. These were all able to be separated and identified using the two labs stated below, without getting into specifics.
I don't accept my current grade, because it is wrong, and my grade should be higher than D in anyhow according to Dr.Scandale's grading policy. The following explanation is made on my behalf. Lab 1.1 grade = 0 "what should be the correct grade?", and if different, explain why
This precipitant was white and looked slightly powdery. The liquid in the round bottom flask was poured into a test tube filled with 15mL of water. When this was done, two layers
Unknown Paper I Introduction This lab is a presentation of lab tests performed to finalize a conclusion based on results to identify the given unknown bacteria. The unknown bacteria was identified based on lab test results in the table provided in class for the possible unknown bacteria. The unknown bacteria identified as #36, and based on the lab tests is Enterobacter II Materials and Methods Catalase Test- this test determines whether bacteria have the enzyme catalase which catalyzes the breaks down hydrogen peroxide.
Sodium Bicarbonate mixed with Hydrochloric acid. The chemical reaction observed showed that there was fizzing and bubbling, this is evidence that a new gas was being produced. This new gas, CO2 was generated from the reaction. After the fizzing stopped a liquid was leftover leading me to conclude the liquid leftover leading me to conclude the liquid leftover was the NaCl and H2O 4. You found a sample of a solution that has a faint odor resembling vinegar (an acid).
Tungsten Carbide is a compound synthesized by the reaction of tungsten (metal) powder and carbon black (carbon powder) at temperatures of 2600° - 2700° F. Tungsten has a chemical symbol "W" which comes from the name "Wolfram" and that is how it is known in Europe. There are a total of thirteen tungsten containing ores of which four types are the most abundant. These are: Wolframite - FeMn(WO 4 ) 2 Scheelite - CaWO 3 Ferberite - FeWO 4 Hubnerite - MnWO 4
Confirmatory tests : confirm the presence of the cation/anion in a given compound. Qualitative tests The addition of hydrochloric acid to solutions containing carbonate or bicarbonate ions or to solid samples of carbonates and bicarbonates causes the rapid evolution (production) of carbon dioxide gas. The equations for the reaction of acid with these ions are: H + (aq) + HCO3 - (aq) → H2O(l) + CO2(g) 2H+ (aq) + CO3
Weighed 1 gram of NaC2H3O2 and mixed it with ionized water. Boiled 12 mL of 1.0M Acetic Acid added into a beaker containing the sodium carbonate on a hot plate until all the liquid is evaporated
TLC was used to identify the actual unknown product as well as other products/reactants present in the filtered solution. The procedure was conducted by placing a TLC plate in a developing chamber that is filled with a small amount of solvent. The solvent cannot be too polar because it will cause spotted compounds on the TLC plate to rise up too fast, while a very non-polar solvent will not allow the spots to move. The polarity of the spots also determines how far it moves on the plate; non-polar spots are higher than polar ones. After spots on the TLC form, the Rf values are calculated and used to analyze the similarity of the compounds.
Determination of the Periodic Properties of the Elements Introduction : Periodic Table shows the properties of elements are periodic functions of their atomic numbers. The periodic table contains alkali metals, alkaline earth metals, transition metal, basic metal, semimetal, non-metal, halogen, noble gases, lanthanides and actinides. The periodic table is important because it is organized to provide a lot of information about elements and how they relate to each other in one easy-to-use reference. It appears in nearly every science lecture room and labs because it is important for science subjects. The periodic table serves a useful purpose.
The appearance of the distillate would support this. After taking the top-half of this sample to be ran through the spectrometer, it was evident that this part of the distillate contained water with a small portion of an unknown sample. Water could be present due to the flow of the condenser. As the vapor gathers on the surface of the copper wire and moves through the condenser channel, picking up water particles is a very reasonable idea. As far as the unknown sample, it seems to lean towards being 2-Butanone.
(Approximate pH ranges for color change: 3.1-4.4) To sum up, back titration is a effective way for the determination of Calcium Carbonate as experimental results were close to it’s true and accepted value of 20%. References Antoine.frostburg.edu, (2014). Acid-Base Indicators. [online] Available at: http://antoine.frostburg.edu/chem/senese/101/acidbase/indicators.shtml [Accessed 12 Dec.