i8o PRACTICAL ORGANIC CHEMISTRY sulphuric acid (10%), 20 ml. Place io ml. (10-3 g.) of aniline in a 150 ml. conical flask, and add slowly 20 ml. (37 g.) of concentrated sulphuric acid; shake the mixture gently during the addition, and keep it cool by immersing the flask occasionally in cold water. White lumps of aniline hydrogen sulphate separate. Add cautiously 20 ml. of io % fuming sulphuric acid (i.e., concentrated sulphuric acid containing 10% of dissolved sulphur trioxide), and then heat the mixture in an oil-bath at 180-190° for i hour, preferably in a fume-cupboard. Allow the product to cool, and pour it carefully into about 200 ml. of cold water, stirring the mixture vigorously during the addition. Allow to stand for about 5 minutes, and then filter off at the pump the sulphanilic acid which has crystal-lised out, wash it well with water, and drain. The crystals so obtained should be almost colourless. Purify by recrystallising from about 250 ml. of boiling water: filter the hot solution
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This note was uploaded on 09/19/2011 for the course CHM 2211 taught by Professor Castalleano during the Fall '06 term at University of Florida.