An Investigation into the Identification, Properties, and Synthesis of an Unknown Ionic Compound

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 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.

5. NaCl, sodium chloride, is a common salt and it burns in the flame test.

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.

In Experiment B the limiting reactant was determined to be CaCl2 when two drops of the test reagent 0.5 M CaCl2 was added to the supernatant liquid in test tube 1, and a precipitate formed. Since there was a reaction, there was C2O42- in excess and Ca2+ is the limiting reactant in the original salt mixture present in test tube 1 . This was further confirmed when two drops of the test reagent .05M K2C2O4 was added to the supernatant liquid in test tube 2. There was no precipitate because Ca2+ was not present since it was the limiting reactant and instead C2O42- was in excess.

We then proceeded in testing for excess Ca2+ by adding two drops of .5 M K2C2O4 to test tube two and attentively observed to see if a precipitate formed, which it did. This meant that Ca2+ was in excess and C2O42- was the limiting reactant in the original salt mixture. We then cleaned up. Upon returning to our next class, we took the filter paper, with the precipitate on it, and took its mass.

Reaction 3- 1. Obtained a clean and dry test tube and placed a small amount ( about the size of a jelly bean) of ammonium carbonate into the test tube.

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.

Experiment 55 consists of devising a separation and purification scheme for a three component mixture. The overall objective is to isolate in pure form two of the three compounds. This was done using extraction, solubility, crystallization and vacuum filtration. The experiment was carried out two times, both of which were successful.

This only matched the description of the compound Calcium Nitrate. To further support the conclusion that Unknown A was indeed the compound Calcium Nitrate, the colors of the flame were observed. They both

Calcium was discovered by Sir Humphry Davy at England in 1808. Calcium is a soft, gray metal. When it burns, it burns with a yellowish-red flame. When it is exposed to air, it develops a gray-white coating because it reacts with the oxygen in the air to form a coating of calcium oxide .Calcium comes from the Latin word calx meaning lime. Compounds such as lime were prepared by the Romans in the first century under the name calx. Literature dating back to about 975 AD notes that plaster of Paris is useful for setting broken bones. Other calcium compounds used in early times include limestone. Calcium metal was not isolated until 1808. After learning that Berzelius and Pontin prepared calcium amalgam by electrolyzing lime in mercury, Sir Humphry

1 Copper (II) Nitrate Crystals in vial, Copper Metal - 6-8 pc. in bag 2"x 3"

Zainulabidin Adhami BB3 Experiment 3: The Gravimetric Determination of Calcium Abstract: The Gravimetric Determination of Calcium Lab utilized homogenous precipitation to determine the percent Calcium (Ca) in an impure sample of Calcium Carbonate (CaCO3). Three samples of 0.3574g, 0.3500g and 0.3736g of an impure sample of Calcium Carbonate (CaCO3) were added to three beakers, two of which were 250 ml and one which was 400 ml. These three samples were reacted with many different substances. After the reaction, presented above, was completed, the solution was promptly put into a vacuum filtration and then subsequently massed.

owing for a percentage yield of 74.###%. A percentage yield of 11#.##% was also calculated, had the