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.
The primary goal of this laboratory project was to identify an unknown compound and determine its chemical and physical properties. First the appearance, odor, solubility, and conductivity of the compound were observed and measured so that they could be compared to those of known compounds. Then the cation present in the compound was identified using the flame test. The identity of the anion present in the compound was deduced through a series of chemical tests (Cooper, 2009).
At this point the identity of the unknown compound was hypothesized to be calcium nitrate. In order to test this hypothesis, both the unknown compound and known compound were reacted with five different compounds and the results of those reactions were compared. It was important to compare the known and unknown compounds quantitatively as well to ensure that they were indeed the same compound. This was accomplished by reacting them both with a third compound which would produce an insoluble salt that could be filtered off and measured.
It was important that the compound was identified correctly so that it could be disposed of properly and so that it might be used for other purposes. Once the quantitative analysis indicated that the compound had been correctly identified, it was also our goal to determine methods of synthesizing the compound and to compare the syntheses for cost effectiveness, safety, and potential yield.
The unknown ionic compound was composed of translucent crystals. It had no odor, was soluble in water, and its electrical conductivity in water was measured at 1.66V, as indicated in Table 1. The compound burned a bright red during the flame test consistent with the flame signature of calcium, as indicated in Table 2, and along with the fact that the compound was soluble in water, this helped us to eliminate the possible presence of the poorly soluble salts (Cooper, 2008). However, tests for these anions were still performed.
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...