REACTIONS AND IDENTIFICATION 369 from fructose (about 5 minutes under above conditions) than from glucose, but little reliance can be placed on this difference unless the two reactions are carried out side by side under strictly parallel con-ditions. 4. " Rapid furfural test." Fructose gives an immediate violet colora-tion on boiling (see Test 4 for glucose). Sucrose. (Cane sugar). 1. Does not reduce ammoniacal silver nitrate or Fehling's solution. If, however, the sucrose solution is warmed for some time with the reagent in question, slight hydrolysis to glucose and fructose does take place and reduction then occurs: occasionally samples of sucrose will rapidly give a silver mirror, presumably owing to impurities. 2. Does not form an osazone. 3. " Rapid furfural test'' A violet coloration is produced immediately on boiling (as for fructose). 4. Hydrolysis by acids. Sucrose is readily hydrolysed by dilute acids. Dissolve 0-5 g. of sucrose in 5 ml. of water, add 2 ml. of dil. H
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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.