1. Family of Elements

2. Families of Elements
Within families of elements (groups) there are general trends in physical and chemical properties
Alkali metals, alkaline earth metals, and halides will be observed in this lab
Identification of these elements will be done by their chemical reactions

3. Flame Tests Flame colors are specific to each element
However, flame tests can be misleading
Contamination can lead to inaccurate results
Sodium as an impurity will give a weak yellow flame, sodium in the sample will produce a strong yellow flame

4. A. Analysis of Known Solutions 1. Flame tests of known solutions
Place 6 test tubes in a test tube rack
Add 10 drops of barium, calcium, lithium, potassium, sodium, and strontium to 6 different test tubes
Obtain a flame-test wire and remove contamination by placing the wire loop at the tip of the burner flame
Continue until there is no longer any color produced in the flame
If wire continues to produce a colored flame, dip in dilute HCl (aq) and heat the wire to read hot
Dip clean wire into the test tube containing the barium solution
Place loop at the tip of the flame
Record observation
Clean wire and repeat the flame test for the other 5 solutions

5. A. Analysis of Known Solutions 2. Reactions of Known Solutions
Add a few drops of ammonium carbonate solution in each test tube that was used for the flame test
If precipitate forms, record ppt in data table
If no reaction, record NR
Clean test tubes and rinse with DI water
Put 10 drops of Ba, Ca, Li, K, Na, Sr into separate test tubes
Add a few drops of ammonium phosphate solution in each test tube
Record observations

6. A. Analysis of Known Solutions 2. Reactions of Known Solutions (cont’d)
Clean test tubes and put 10 drops of Ba, Ca, Li, K, Na, Sr into separate test tubes
Add a few drops of ammonium sulfate solution in each test tube
Record observations

7. A. Analysis of Known Solutions 3. Halide tests of known solutions
Place 3 test tubes in a test tube rack
Add 10 drops of Br, Cl, and I solution in separate test tubes
Add 10 drops of hexane, 1 drop of nitric acid and a few drops of Cl water to each test tube
Shake each test tube and observe the color of the upper hexane layer
DISPOSE OF HEXANE LAYER IN WASTE CONTAINER PROVIDED

8. B. Analysis of an Unknown Solution 1. Flame Test
Record the unknown number of solution
Perform a flame test on solution
Record observations

9. B. Analysis of an Unknown Solution 2. Solution Reactions
Put 10 drops of unknown solution into 3 test tubes
Add a few drops of
Ammonium carbonate to the first test tube
Ammonium phosphate to the second test tube
Ammonium sulfate to the third test tube
Record your observations

10. B. Analysis of an Unknown Solution 3. Halide Test
Put 10 drops of unknown solution into a test tube
Add 10 drops of hexane, 1 drop of nitric acid, and a few drops of chlorine water
Shake test tube
Record the color of the upper hexane layer

11. Notes Note that problem #10 is not optional Bunsen burners:
If you have long hair you must have it pulled back (pony tail)
No long dangly sleeves, coats, jewelry