Discussion Of Results And Scientific Explanations

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.

In a chemistry stockroom, a vial of an Unknown White Compound was found. In order to properly dispose of the substance, the substance has to be identified .The possible compounds has been limited to one of 15 different compounds. Also, approximately 5 grams of the Unknown White Compound (UWC) were available for testing. In order to determine the properties of the compound, a series of tests was conducted. These tests included a ph test, a conductivity test, a flame test, a sulfate test, a halide test, an ammonium test, a solubility test, and a carbonate test. Using the results of these experiments, it was hypothesized that the UWC is potassium chloride. To further confirm the hypothesis, a synthesis of potassium chloride was conducted.

Unknown white compound (823U) was discovered in the lab. In order to dispose of it correctly, the substance and its physical and chemical properties had to be identified. The unknown white compound was one of a list of 15 compounds. 5g of the unknown compound were given in order to correctly identify and discover its physical and chemical properties. In order to do so, a solubility test, a flame test, and ion tests were conducted. From the results of these initial tests and the given list of compounds, the unknown white compound was thought to be composed of sodium and a halide (I-, Br-, or Cl-). Of the list, NaCl was the appropriate compound, however NaC2H3O3 was also tested out of skepticism. To verify the identity of the substance, the solubility and flame tests were performed again along with a pH test. The pH tests of NaCl and NaC2H3O2 did not match that of the unknown white compound. The list of compounds had been entirely ruled out. The identity of the unknown white compound was revealed to be calcium chloride. To synthesize at least a gram (calculated to produce 1.2g) of CaCl2, the following reaction was completed.

The white color implies that chlorine is within the mineral oil, thus did not react. Since chlorine did not react, it means that bromide isn’t a possible anion, leaving chlorine as the anion. In procedure 5, the unknown compound produced water on the watch glass indicating it could be a hydrate. The hydrate test was inconclusive because the number of waters of hydration shown in Table 5 was half way between being lithium chloride monohydrate and lithium chloride 2. The percent error, shown in Table 5, between the expected percent of water in lithium monohydrate and the accepted value, was high at 40% which meant that the unknown could not be properly identified as a hydrate. Repeating the hydrate test produced a similar percent which is shown in Table 7. The reason for these high percent errors is because lithium chloride and lithium monohydrate are both hygroscopic. In addition, Table 6 shows an increase in mass when unknown #42 was left outside, which suggest that the unknown compound is

Ionic compounds are soluble in water to a certain point depending on the compound. The level of solubility changes among different compounds. Some ionic compounds can completely dissolve in water and appear to be a homogeneous mixture. Although, some ionic compounds dissolve very little, and could be considered insoluble, since it does not dissolve fully. Depending on the compound, the level of solubility can be high or low. However, ionic compounds could dissolve to a certain degree. If the solution appears to be a heterogeneous mixture, many may assume through visual representation that it may be insoluble. As stated previously, the smallest amount of solubility should be considered. To confirm whether or not the substance is soluble, observe the efficiency when conducting electricity. Due to practical reasons, the slightest solubility could be considered insoluble by people.

This paper describes the methods used in the identification, investigation of properties, and synthesis of an unknown compound. The compound was identified as calcium nitrate by a variety of tests. When the compound was received, it was already known to be one of twelve possible ionic compounds. The flame test identified the presence of the calcium anion in the compound. The compound tested positive for the nitrate cation using the iron sulfate test. At this point it was hypothesized that the compound was calcium nitrate. Reactivity tests and quantitative analysis comparing the unknown compound with calcium nitrate supported this hypothesis. Synthesis reactions were then carried out and analyzed.

What Is The Unknown White Compound By Alexander Medina Lab Partners Maxwell Yurs, Eugene Floersch, Mesih Harri Abstract A white compound is found, but its identity is unknown.

By identifying the solubility of the unknown, it could lead to a closer interpretation as to what the functional group the unknown may be. Solubility is determined based on intermolecular attractive forces, such as hydrogen bonding, dipole-dipole, and London dispersion forces. Intermolecular attractive forces arise due to different electron environments in different molecules. For example, water molecules are good at dissolving

Continually, the solution was allow to cool down, before it was reheated to dissolve the solid. The solution stood undisturbed until crystals were formed. Solubility tests were performed on all possible solvent-solute pairings. The most efficient pair was

The purpose of this experiment is to identify an unknown substance by measuring the density and boiling point. I will be able to conclude which substance is my own from a list of known options stating what its real boiling point and density is.

In this lab, lab 4.3 Comparing the Concentrations of Saturated Solutions, we set out to find and compare the solubilities of two solids in water. In addition, we tested if solubility is a characteristic property of a solid in a given liquid. This lab allowed us to test and use a reliable way to measure the solubility of a solid. This lab can be replicated for any solid with the same procedure, thus it gives us a method to calculate solubility. The two solids we tested in this experiment were NaCl (Sodium Chloride) and NaNO3 (Sodium Nitrate).

The result was small white crystals, which were dry and had barely contained any moisture. The product was then dissolved in methylene chloride and dried with granular anhydrous sodium sulfate. The drying agent would have removed any water in the solution and presented a colorless solution. The solvent was evaporated and the product was collected; it had the appearance of small, white solids. Data Table 2 shows the results and calculations that were gathered after the completion of this experiment. A boiling point of the product was found to be 210℃. According to literature, the boiling of isoborneol should be 212℃. As a result, the product is most likely isoborneol. No errors had occurred during the course of the experiment, which is testified by the high yield of

Suppose a friend or peer approaches you and asks you to revise an essay he or she wrote. The essay contains several grammatical, spelling, and punctuation errors. Do you truthfully tell your friend that his or her essay needs a considerable amount of changes, or do you temper the truth and tell him or her that their essay could use only a couple tweaks and let them figure out the rest? In most situations it is better to give the absolute truth, even though it might sound hurtful and be hard to say. Giving the absolute truth is better for the person you are telling it to because he or she could learn or gain something from it. For instance, in the short story “Like the Sun”, Sekhar’s headmaster asks him to critique his music. Although Sekhar

Qualitative analysis is the use of experimental processes to identify the chemical parts of a substance. The knowledge of the meaning of soluble and insoluble is key to completing this experiment correctly and accurately. Soluble means that a compound readily dissolves in water and insoluble means that compounds do not dissolve in water. A precipitate is formed when two soluble compounds combine to form an insoluble compound. All nitrate solutions are soluble; therefore, the known solution was formed by dissolving nitrate salts of all the cations in the experiment in De-Ionized water. A centrifuge was used in each step of the experiment to spin

In the scientific community, there are numerous models used to explain data, which despite being argued over, can be used to spread knowledge. One model proposed by Hempel is the “Covering Law Model,” which can be explained when he writes: “The kind of explanation thus characterized I will call deductive nomological explanation; for it amounts to a deductive subsumption of the explanandum under principles which have the character of general laws” (Hempel, 658). Essentially, the D-N model explains scientific explanation as deductive, requiring the truth of its premises to ensure the truth of the conclusion, which also must be backed up by an accurate prediction of whichever phenomenon is being explained. However, there are problems with this model, as explained by Kim when he writes: “In a nutshell, then, the trouble is that we have had models, but not theories, of explanation” (Kim, 53). Hempel’s critics want to include metaphysics under explanation, which would essentially mean putting more emphasis on causal factors to make sense of the world, rather than using readily explainable phenomenon like gravitational pull. Though they have their disagreements with each other, I believe that both methods have merit, and adding causal realism to the Covering Law Model is currently the best solution to explaining scientific concepts.