WHY SODIUM FUSIONS? Sodium reacts violently with water. Extreme caution must be exercised. WHY SODIUM FUSIONS? Organic compounds usually contain carbon, hydrogen, and oxygen. Other element that may be present are: nitrogen, sulfur, and halogens. These latter three elements are usually bound covalently, and are NOT water soluble. The detection of these depends on converting them into water-soluble ions: CN -, S 2-, and X -. This is usually done by a “sodium fusion”. Sodium reacts violently with water. Extreme caution must be exercised.
You need a 50 mL beaker half full with distilled water, a Bunsen burner, a sample ground to a very fine powder, and a clean DRY 3-inch test tube held in a test tube holder. You need a 50 mL beaker half full with distilled water, a Bunsen burner, a sample ground to a very fine powder, and a clean DRY 3-inch test tube held in a test tube holder. Be sure the beaker of water is placed under your snorkel. under your snorkel.
With a paper towel, blot dry a small piece of sodium and place it into the test tube. Over a low flame, heat the sodium until it melts into a shiny, silvery ball and vapors start to rise in the test tube.
Remove the tube from the flame and add a bit of the powdered sample. There may be a bit of a reaction when you do this... You may re-heat, and add more sample if you wish.
Finally, re-heat the tube to a dull red Move the tube from side to side to avoid burning out the bottom of the tube.
When the tube is RED HOT, PLACE (do not DROP) the tube into the beaker of water. Be sure the tube is not pointed at you, nor at anyone else at this time. The tube should SHATTER! Expect a rather vigorous reaction, -- perhaps with fire and smoke.
Heat the solution to boiling for a few minutes (Fig. 1). Then, gravity filter (Fig. 2) to remove broken glass and solid residue. The clear filtrate is used to test for sulfur, nitrogen, and halogens.
Some may prefer to use hot plates
Conduct the tests on the “KNOWN”, for sulfur, nitrogen, and halogens, as directed (p. 45) in your lab manual. When your Lab Instructor approves your tests, conduct the sodium fusion tests on the “UNKNOWNS” which are provided.
Your Laboratory Report Form is due the day on which you perform the Sodium Fusions. Be prepared to turn it in.