Discussion of the Results and the Scientific Explanation
The purpose of this experiment was to identify an unknown compound and discover its properties by devising experimental designs that enable for its identification (Cooper, 2009). Fifteen possible compounds were given, and a series of qualitative tests were used to eliminate the different possibilities and identify the specific unknown compound. These tests included a solubility test, which determines whether the compound is soluble in water, a pH test to determine the relative acidity of the compound, and a flame test, which shows the presence or absence of metal ions, and an anion test. The compound was then tested with five other known compounds to provide more evidence of the true …show more content…
An excess of water was put into an erlenmeyer flask and weighed, resulting in a weight of 90.3grams. The water was heated as the unknown was added. The unknown was added until it could no longer dissolve. Afterwards, the flask was weighed again, weighing 91.072 grams, indicating that the weight of the dissolved solute was .76 grams. The reaction was as follows: Ca + 2H2O-> Ca(OH)2 + H2 . The Calcium in the unknown reacted with water, rather than dissolving. Nitrate is always soluble in water, but calcium will form a precipitate of Ca(OH)2 since it reacts with water. The precipitate will have a solubility 0.79g/15mL, or …show more content…
After the anion testing was conducted for the known compounds, it was repeated with the unknown compound. If any of the anion tests create a reaction with the unknown compound, then the known anion is the anion of the unknown compound. For the carbonate test, 1mL of known compound containing carbonate was added to a test tube. 6M HCL was added very slowly to the test tube in order to detect any effervescence. The reaction resulted in effervescence, so carbonate is the anion. When the carbonate test was conducted with the unknown, no reaction occurred, leading to evidence of the absence of carbonate in the unknown. For the sulfate test, a few drops of Barium chloride was added followed by a few drops of HCl to a known compound. Formation of a milky white precipitate BaSO4 proves presence of sulfate ion. The same reaction was run again, only with the unknown. No precipitate formed, so sulfate is not present in the unknown compound. For the chloride test, HNO3 was added to the known compound, followed by AgNO3. A white precipitate of silver chloride is formed, confirming the positive result of chloride ion. When the test was repeated with the unknown, a white precipitate also formed, indicating the presence of chloride ions in the unknown. However, the presence of chloride ions does not provide sufficient evidence that chloride is the anion of
The purpose of this experiment was to identify an unknown compound and discover its properties by devising experimental designs that enable for its identification (Cooper, 2009). Fifteen possible compounds were given, and a series of qualitative tests were used to eliminate the different possibilities and identify the specific unknown compound. These tests included a solubility test, which determines whether the compound is soluble in water, a pH test to determine the relative acidity of the compound, and a flame test, which shows the presence or absence of metal ions, and an anion test. The compound was then tested with five other known compounds to provide more evidence of the true …show more content…
An excess of water was put into an erlenmeyer flask and weighed, resulting in a weight of 90.3grams. The water was heated as the unknown was added. The unknown was added until it could no longer dissolve. Afterwards, the flask was weighed again, weighing 91.072 grams, indicating that the weight of the dissolved solute was .76 grams. The reaction was as follows: Ca + 2H2O-> Ca(OH)2 + H2 . The Calcium in the unknown reacted with water, rather than dissolving. Nitrate is always soluble in water, but calcium will form a precipitate of Ca(OH)2 since it reacts with water. The precipitate will have a solubility 0.79g/15mL, or …show more content…
After the anion testing was conducted for the known compounds, it was repeated with the unknown compound. If any of the anion tests create a reaction with the unknown compound, then the known anion is the anion of the unknown compound. For the carbonate test, 1mL of known compound containing carbonate was added to a test tube. 6M HCL was added very slowly to the test tube in order to detect any effervescence. The reaction resulted in effervescence, so carbonate is the anion. When the carbonate test was conducted with the unknown, no reaction occurred, leading to evidence of the absence of carbonate in the unknown. For the sulfate test, a few drops of Barium chloride was added followed by a few drops of HCl to a known compound. Formation of a milky white precipitate BaSO4 proves presence of sulfate ion. The same reaction was run again, only with the unknown. No precipitate formed, so sulfate is not present in the unknown compound. For the chloride test, HNO3 was added to the known compound, followed by AgNO3. A white precipitate of silver chloride is formed, confirming the positive result of chloride ion. When the test was repeated with the unknown, a white precipitate also formed, indicating the presence of chloride ions in the unknown. However, the presence of chloride ions does not provide sufficient evidence that chloride is the anion of