CHM 100-Introduction to Chemistry

 

Experiment #7 – Periodic Classification of the Elements

 

REVISED INSTRUCTIONS…

 

 

Part A:  Flame Tests

  There are 6 beakers containing wood splints soaking in barium, calcium, lithium, potassium, sodium and strontium solutions.  Using a pair of tongs, remove one of the wood splints from the metal ion solution.  Still using the tongs, place the tip of the splint just above the light blue inner cone of the Bunsen burner.  Record the color of the flame.  Do the same for the other 5 metal ion solutions.

 

 

Part B:  Reactions of the Alkali & Alkaline Earth Elements

1)      Place 2 drops of barium, calcium, lithium, potassium, sodium and strontium solutions into separate wells on a spot plate.  Add 1 drop of ammonium carbonate to each well.  If a precipitate (ppt) forms, record “ppt” in the data table.  If there is no reaction, record “NR” in the data table.  Clean the spot plate and rinse with distilled water.

2)      Place 2 drops of barium, calcium, lithium, potassium, sodium and strontium solutions into separate wells on a spot plate.  Add 1 drop of ammonium phosphate to each well.  Record your results.  Clean the spot plate and return it to the side counter. 

3)      Place 2 drops of barium, calcium, lithium, potassium, sodium and strontium solutions into separate test tubes.  Add 1 drop of ammonium sulfate to each test tube.  Record your results (**place your test tube containing calcium and ammonium sulfate in the communal hot water bath for approximately 1 minute before you make an observation).

 

 

Part C:  Halides

  OMIT this part

 

 

Part D:  Unknown

1)      Record the number of your unknown. 

2)      Take a clean wood splint and soak it in the unknown solution for approximately 1 minute.  Do a flame test and record the color. 

3)      Clean 3 test tubes.  To each test tube, add 4 drops of your unknown.  Add 2 drop of ammonium carbonate to the 1st tube; 2 drop of ammonium phosphate to the 2nd tube and 2 drop of ammonium sulfate to the 3rd tube.  Record your results.

4)      Identify the unknown metal ion. 

 

 

*** Please return this sheet to your lab instructor at the end of the lab. ***

***  Thank You!  ***