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. In order to properly dispose of this unknown substance, several tests needed to be performed in order to identify the substance. A flame test, pH test, and conductivity test are used to narrow the identity of the compound. After identifying the compound, its identity needs to be proven by a flame test, pH test, and conductivity test. Afterword, one gram of the unknown compound needs to be synthesized. It was determined that the most likely identity for the unknown compound was either Ca(NO3)2, CaCl2, or CaCO3. After redoing the flame …show more content…
Gather 0.61 grams of CaCO3 and 0.768 grams of HNO3, a 250 mL beaker, distilled water, and a heating pad. Put the compounds into the 250 mL beaker and add distilled water. Stir until the compounds are dissolved in the water. After the reaction is done, place the beaker onto a heating pad to evaporate the water. Scrape the remaining compound out of the beaker and mass it. Determine the percent yield. Preform a flame test, pH test, and a conductivity test to determine if the made compound is Ca(NO3)2. Results Flame test: The flame test had a variety of results. Most of the known compounds did not match our unknown except for Ca(NO3)2. Both Ca(NO3)2 and the unknown compound had a deep red/orange color flame. While Ca(NO3)2 had the closest results two other compounds had slightly different results but not different enough to rule them out. Those other two compounds were CaCl2 with a yellow/ orange color and CaCO3 with a reddish color. Since NaCL, KCl, and MgCl2 are not even close to the color of the unknown, these three compounds can be eliminated from the list of the possible identity of the unknown compound. Compound Color of flame unknown Deep red/ …show more content…
If solid CaCO3 is combined with an aqueous solution of HNO3, Ca(NO3)2 as well as CO2 and H2O will form. The chemical equation for this reaction is CaCO3 (s) + 2 HNO3 (aq) → Ca(NO3)2 (aq) + CO2 (g) + H2O (l). To theoretically make one gram of Ca(NO3)2, 0.61 grams of CaCO3 need to be added with 0.768 grams of HNO3. Adding this two compounds will release CO2 gas into the air and will also from H2O to our compound. To get rid of the water and crystalize our compound, heat the beaker with the solution on a heating plate to evaporate the H2O. After letting the compound cool down, scape it onto a piece of paper and measure it’s mass. The mass of the compound was 0.806 grams. This means that there was a percent yield of 80.6%. Looking at the table it appears that the synthesized compound is Ca(NO3)2. The synthesized compound has the same color for the flame test, the same pH level, and the mean value from the conductivity test was extremely
1. Which reactants used in this experiment are flammable? Discuss the safety precautions that are necessary when working with flammable materials in the lab?
Suppose a household product label says it contains NaHCO3. How would you test this material for the presence of sodium bicarbonate?
1 Copper (II) Nitrate Crystals in vial, Copper Metal - 6-8 pc. in bag 2"x 3"
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.
To verify that CaCl2 was the compound that had been synthesized, the compound was tested with the flame test, solubility test, halide ion test, and pH test. CaCl2 was confirmed to be the synthesized compound as the results of these tests matched the results of the unknown white compound.Introduction
Based the data collected, the identity of the unknown #42 is lithium chloride. Because the unknown compound produced a bright red pinkish flame, shown in Table 1, the possible cations based on the CRC Handbook were lithium or strontium 1.The known 1M lithium chloride also produced the same colored flame as the unknown, suggesting that the unknown compound has lithium. Since lithium produces no precipitate with the compounds in Table 2 and strontium produces a precipitate with the same compounds, the observations in Table 2 indicate that the unknown’s cation is lithium 4. Using the solubility table, process of elimination, and the results in Table 3 the possible anions for the unknown compound were chloride and bromide4. The production of precipitate
The compound was tested for the presence of ammonium, carbonate, sulfate, chloride, and nitrate, as seen in Table 2. The nitrate test produced a precipitate, indicating the presence of the nitrate ion in the compound. At this point it was hypothesized that our unknown compound was calcium nitrate.
We repeated this for a total of 6 known substances and 3 unknown substances. We also made a table for each element showing the color of the flame that we saw,
Even though the compounds provided in this lab did not come with any information, one must use their knowledge and investigative skills to formulate their own justifications for the unknown substances through performing a wide variety of tests. To elaborate, these trials are crucial for solving the identity of these compounds as each of their characteristics that they exhibit (the outcome of the experiments) are directly connected to a specific chemical compound group, whether it be metallic, ionic, polar covalent, non-polar covalent or network covalent. Unknown compound #1 and #4: First of all, it is most certain that the first and fourth unknown compounds should be classified as an ionic since their qualitative and quantitative properties
An unknown sample was massed and put into three test tubes for three different trials. A gas transfer assembly was put together and hydrochloric acid was added to each sample in each test tube. A reaction between the carbonate sample and the acid occurred and the volume of carbon dioxide gas produced was recorded. This process was repeated three times. The mass
We used a Bunsen burner, Ni-Cr wire, and the eight different metal ions for this lab. We had to place several drops from one of the solutions on the end of the Ni-Cr wire, then one person holds the wire in the flame, and the others observe the colors of each solution through the spectroscope, then record data, and then repeat each step for the other solutions. When done, clean the wire and any spills and turn off the Bunsen burner. For the unknown substance (number 3), we found out that it was barium because when we did the flame test on barium, it’s flame color was yellow and it was yellow for the unknown too. Also, the unknown and barium had the same colors on the spectroscope reading and the three colors were close to being on the same number, and the unknown didn’t fit with any of the other solutions’
A unknown was assigned by the lab instructor which contained 4-aminobenzoate, Naphthalene, and Benzoic acid. The name of this unknown was Unknown B. This unknown was mixed with 2ml of methylene chloride which separated into an organic and an aqueous layer. The aqueous layer was on top.
One of the tests carried out in this investigation is a flame test. A flame test is crucial in order to be able to identify
Sodium hydrogen carbonate was added to the solution until it becomes neutral. Ph paper was used for this test to determine its ph value.
Perhaps had the lab been executed slightly differently, a different trend would have been found, or possibly the data would have supported the hypothesis. While only given one class period to complete this lab, it is possible that it was slightly rushed, resulting in different results. Additionally, it would have been beneficial to test each element more than once to ensure that the most accurate information was being gathered. This may have led to unexpected results as something may have gone wrong with the Spectrometer and its data collection. It is also a possibility that the Spectrometer was not given enough time to fully collect the data. Perhaps it was not close enough to the flame, or it was turned off before it was finished gathering information.