Salt Solubility Experiment

Based on some of the result from our last salt solubilities experiment and along other results we were able to find the name of a unknown inorganic salt composed of one cation and one anion. For the following experiment, test like pH of solution, behavior towards Hydrochloric acid, nitric acid, sulfuric acid, sodium oxide, silver nitrate and ho ti reacts with water and fire will help us determine the identity of the unknown solution.

The first step was to classify the unknown solution based on appearance and texture. Solution 15, which was the unknow had a blue crystalline color, mixed with white. Table 2 gives some suggestion about the color of each inorganic salts. By appearance it can be predicted that the solution contains Cobalt, or Copper.

In a different test tube 6M of hydrochloric acid was mixed some of the solution. The solution was [placed first and then drop by drop the hydrochloric acid. After stirring thoroughly the solution turned yellowish-green. If the salt did not dissolved in water but it did in the acid indicates that carbonate, hydroxides, phosphates or sulfides might be present. Those options can be ruled out because the unknown did dissolve in both waters and hydrochloric acid. Table 4 indicates the presence of cobalt and copper for the given solution color. The same thing was done for the nitric and sulfuric acid. The unknown dissolved with both nitric acid and sulfuric acid.

Along withe the behavior in acids, the flame est was also conducted in order to see the interaction between the cations and flame. Based on the flame test and table 5 the possibilities were barium and copper. Copper reacted with fire to form a green color with blue edges. The barium produced a yellow- green color. We know that the solution can not contain barium because previously it was said that sulfates are soluble except when barium is present. The unknown was soluble meaning that barum couldn't be part of the components on the

If the solution forms a precipitate that means that the unknow is soluble. In a 10*75 mm test tube ten drops of the unknow mixed with water and add 6M of the sodium hydroxide. The solution formed a precipitate. Dark solid started to form in the bottom after leaving the solution sit for several minutes. The solution turned green and a few blue spots at the bottom. The solution with silver nitrate a precipitate was formed. The solution was light blue, it was warm to the touch and white spots formed at the bottom. Based of table 6 the suggestions for the possible anions were silver sulphate due the white spots that formed at the bottom of the solution. It could also be hydroxide or sulfide due to the black sports that frames. However phosphates and sulfides are insoluble in water and they can be ruled out of the possibilities.

The last test taken was the presence of covalent bonds though the infrared spectra. The spectra will show the frequency in the covalent bond vibration. The scanning shows a strong covalent bond between sulfur and oxygen. The dips were sharp and strong for sulfate. You can predict that the unknown certainly had the anion sulfate in