Qualitative Anion Tests
Exercise 14: Qualitative Anion Tests
PURPOSE:
The purpose of this experiment is to identify some commonly occurring anions & to study some of the reactions used for their identification.
PROCEDURE:
You must first determine to which of the three groups the various anions belong. Since no two people observe the same event in exactly the same way it is important to also conduct specific confirmation tests on the known samples of each anion. This information will help identify the anion present in the unknown solution. After determining to which group the unknown solution belongs the specific confirmation test will enable you to conclusively identify which anion is present in the unknown solution.
1. Before beginning, set up a data table similar to the Data Table: Qualitative Anion Tests in the
Lab Report Assistant section.
2. Each anion tested will require the use of three separate test tubes. Complete all of the following tests on one solution, record your observations, and then thoroughly clean and dry the test tubes before beginning tests on the next solution.
3. After consecutively testing the identified anions, perform the same tests on the unknown solution to conclusively determine its identity.
4. First test tube: a. Put 8 drops of the anion to be tested in a clean small test tube. b. Add 8 drops of hydrochloric acid to the anion solution. Note the appearance of the solution plus any evolution of gas and odors of gas.
5. Second test tube: a. Put 8 drops of the anion solution in a second test tube. b. Add 3 drops of silver nitrate solution. c. Note the colors of any precipitates formed. d. Write a net ionic equation for any reaction that produces a precipitate. e. Acidify the test tube by adding a few drops of nitric acid. f. Mix well and note if the precipitate dissolves or remains.
6. Third test tube: Per the following, perform the appropriate confirmation test for this anion.
NOTE: Where the following
PURPOSE:
The purpose of this experiment is to identify some commonly occurring anions & to study some of the reactions used for their identification.
PROCEDURE:
You must first determine to which of the three groups the various anions belong. Since no two people observe the same event in exactly the same way it is important to also conduct specific confirmation tests on the known samples of each anion. This information will help identify the anion present in the unknown solution. After determining to which group the unknown solution belongs the specific confirmation test will enable you to conclusively identify which anion is present in the unknown solution.
1. Before beginning, set up a data table similar to the Data Table: Qualitative Anion Tests in the
Lab Report Assistant section.
2. Each anion tested will require the use of three separate test tubes. Complete all of the following tests on one solution, record your observations, and then thoroughly clean and dry the test tubes before beginning tests on the next solution.
3. After consecutively testing the identified anions, perform the same tests on the unknown solution to conclusively determine its identity.
4. First test tube: a. Put 8 drops of the anion to be tested in a clean small test tube. b. Add 8 drops of hydrochloric acid to the anion solution. Note the appearance of the solution plus any evolution of gas and odors of gas.
5. Second test tube: a. Put 8 drops of the anion solution in a second test tube. b. Add 3 drops of silver nitrate solution. c. Note the colors of any precipitates formed. d. Write a net ionic equation for any reaction that produces a precipitate. e. Acidify the test tube by adding a few drops of nitric acid. f. Mix well and note if the precipitate dissolves or remains.
6. Third test tube: Per the following, perform the appropriate confirmation test for this anion.
NOTE: Where the following