Chloroform and Aluminum Chloride test
Procedure
To 2 mL of dry chloroform in a test tube add 0.1 mL or 0.1 g of the unknown compound. Mix thoroughly, and incline the test tube so as to moisten the wall. Then add 0.5-1.0 g of anhydrous aluminum chloride so that some of the powder strikes the side of the test tube. Note the color of the powder on the side, as well as the solution. Discussion. The colors produced by the reaction of aromatic compounds with chloroform and aluminum chloride are quite characteristic. Aliphatic compounds, which are insoluble in sulfuric acid, give no color or only a very light yellow. Typical colors produced are the following.
Positive Test
Formation of a colored carbocation is a positive test.
Compound Color
benzene and its homologs orange to red
aryl halides orange to red
naphthalene blue
biphenyl purple
phenanthrene purple
anthracene green
Complications
Aromatic esters, ketones, amines, and other oxygen- or nitrogen-containing compounds may also give blue or green colors.
No comments:
Post a Comment