Homework Soursedid glucose give a positive tollens phloroglucinol test woul
did glucose give a positive tollen\'s phloroglucinol test? would fheling test confirm unequivocally the presence of this carbohydrate? explain (please give the explanation)
Solution
Add 0.2 ml of sugar solution to 2.0 ml of the reagent in the test tube. Heat the tube for 15 minutes in the water bath. The appearance of a red color is a positive test. The test is given by pentoses, galactose and glucuronic acid.
The color is due to the formation of furfural phloroglucnide with furfural and phloroglucinol,the former is formed by the action of acid on pentoses.
Glucose does not give phloroglucinol test
Fehling\'s solution is a chemical test used to differentiate between water-soluble carbohydrate and ketone functional groups, and as a test for monosaccharides. The test was developed by German chemist Hermann von Fehling in 1849
yes , it confirms the prescence of carbohydrates
