PREPARATIONS 171 mixture vigorously an emulsion of the phenol in the water is thus obtained. Now place a thermometer in the dilute nitric acid, cool the latter in ice-water, and add the phenol emulsion in small quantities at a time so that the temperature of the well-shaken mixture does not rise above 30°. When the addition of the phenol is complete, remove the flask from the ice-water and allow the mixture to stand for at least 2 hours—and preferably over-night. During the first hour of this period of standing, retain the thermometer in the liquid and occasionally shake the latter vigorously to ensure thorough mixing: the temperature will spontaneously rise slowly to 50-55° but should not be allowed to rise above this upper limit. If the mixture is allowed to stand for only 2 hours, chill it thoroughly in ice-water at the end of this period in order to coagulate and partly harden the black syrupy insoluble residue and so obtain a sharp separation between this heavy residue and the aqueous layer above. (If the mixture
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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.