Flame Test Lab Report

An unidentified compound was found in a landfill and the group was ordered to investigate and identify the unknown substance. Figuring out the physical and chemical properties was needed in order to make predications on how the compound might behave. Syntheses of the compound were devised to figure out cost effectiveness, safety, and potential yield of the newly identified compound. Final results established that the unknown compound was NaCl. (1)
Initial observations concluded that physically the unknown compound consisted of minuscule white but somewhat colorless crystals.
As shown in Table 1, for the solubility test, the unknown compound was put into the three solvents toluene, acetone and water. When mixed with toluene and acetone, the

This discovery was found through a flame test. When the unknown compound was burned, a bright, vibrant orange flame color resulted. According to the lab manual chart, a compound that lets off an orange colored flame contains sodium (1). To confirm that the compound did in fact contain sodium, 4 additional flame tests were performed: sodium, potassium, magnesium and calcium. As seen in Table 2, both the unknown and sodium produced a consistent orange flame. Potassium omitted purple light, magnesium showed no change in color, and calcium produced a red light. When heated, due to the excited movement of the electrons specifically in the metal ions within the compound, flame colors are produced (2). The structure of a sodium ion in its ground state is 1s22s22p6 (6). When heat is applied, its electrons then gain energy giving them the ability to jump into empty orbitals at high levels (2). Once the electrons reach a higher level however, they become unstable. The electrons then usually fall back, sometimes at different stages, to where they originally were (2). A certain color corresponds to the particular amount of light energy being released with each jump that is occurring (4). A spectrum of colored lines is produced. For sodium, the difference from one energy level to the next corresponds to the wavelength of orange; therefore it produced an

A formation of a white precipitate (AgCl) showed the presence of the chloride ion, Cl-. As the lab manual states, if a precipitate is formed, this test ultimately gives positive results for a halogen or sulfate, since silver salts are also insoluble (1). However, shown in Table 3, when mixing the unknown to find nitrate, carbonate, and sulfate, no positive results were produced. For the anion test, a white precipitate of silver chloride (AgCl) was formed when a solution of AgNO3 was added to the solution of NaCl. In this double-displacement reaction, all the states of the reactants are aqueous, which means they are dissolved in water (6). The insoluble precipitate, AgCl, is a solid. NaNO3 is aqueous because it's soluble in water. AgCl precipitated out of the solution because it's insoluble in water (7). If an ion is insoluble, then it forms a solid with an ion from the other reactant (7). The chemical equation