This experiment is from the official website of Jimei University
Operation method
Experiments on the properties of saccharides
Materials and Instruments
Glucose Sucrose Fructose Maltose Lactose Starch Ferring's Reagent Benedict's Reagent Silver Nitrate Ammonia Sodium Hydroxide Sodium Hydroxide Alpha Naphthol Ethanol Reagent Sulfuric Acid Resorcinol Hydrochloric Acid Reagent Iodine Hydrochloric Acid Reagent Cotton Nitric Acid Ethanol Ether Filter Paper Move 1.Molish test - α-naphthol test for sugar For more product details, please visit Aladdin Scientific website.
Alcohol lamp Test tube holders Test tubes Surface dishes Crucibles
Add 1ml of 5% glucose to a test tube, add 2 drops of 10% α-naphthol and 95% ethanol solution, tilt the test tube 450 and slowly add 1ml of concentrated sulfuric acid along the wall of the tube and observe the phenomenon. If there is no color, heat in a water bath and observe the result again.
Samples: 5% glucose, fructose, maltose, sucrose, starch solution, filter paper pulp
2. Resorcinol test
Add 2 ml of resorcinol to the test tube, add 1 ml of 5% glucose solution, mix well, and heat it in a boiling water bath for 1-2 min to observe any change in color. After heating for 20min, observe again and explain.
Samples: 5% glucose, fructose, maltose, sucrose
3. Benedict's reagent, Tollen's reagent detects reducing sugar
(1) Reaction with Benedict's reagent: take 6 test tubes and add 1ml of Benedict's reagent respectively, heat them slightly to boiling, add 5% glucose solution respectively, heat them for 2-3min in a boiling water bath and observe the phenomenon by letting them cool.
Samples: 5% glucose, fructose, maltose, sucrose, lactose, starch
(2) Reaction with Tollen's reagent: take 6 clean test tubes and add 1.5 ml of Tollen's reagent respectively, add 0.5 ml of 5% glucose solution respectively, and heat it up in a hot water bath at 60-80°C. Observe and compare the results and explain why.
Samples: 5% glucose, fructose, maltose, sucrose, starch solution, filter paper pulp
4. Glycoryzine generation
Take 5 test tubes and add 2 ml of phenylhydrazine reagent to them respectively, add 5% glucose, fructose, lactose, maltose and sucrose solution respectively, heat them in a boiling water bath and check the formation of the crystals and the time taken.
5. Starch hydrolysis
Take 1 test tube and add 3 ml of starch solution, add 0.5 ml of dilute hydrochloric acid and boil for 5min After cooling, neutralize with 10% NaOH and use this hydrolysate for Fehling's test.