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The structure and function of carbohydrates
The structure and function of carbohydrates
The structure and function of carbohydrates
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Introduction: One equivalent of an aromatic aldehyde, two equivalent of an ethyl acetoacetate, and one equivalent of ammonia on refluxing in an alcohol to give Hantzsch ester. The first step, the condensation of acetoacetate with the aryl aldehyde,known as the Knoevenagel reaction. In the second step, the other half of the molecule can be assembled from ammonia and the second equivalent of acetoacetate; the product is an enamine, which is known as Stork enamine reaction. The third step is conjugate Michael addition and the final tautomerization have the driving force of a stable ring size and extended cross-conjugation in the final Hantzsch ester. Reaction: Procedure: Add 7.5 mL 40% formaldehyde to 0oC cooled 25.5 mL 0.2 mole ethyl acetoacetate It can be prepared from phthalic anhydride and resorcinol in the presence of zinc chloride by the Friedel-Crafts reaction. Eosin is a fluorescent red dye produce by bromination of fluorescein. Reaction: Phthalic anhydride Resorcinol Fluorescein Fluorescein Eosin Procedure: Preparation of fluorescein Grind 1.5 g. Phthalic anhydride and 2.2 g. of resorcinol and heat the mixture in oil bath to 180°C. Meanwhile fuse 0.7 g of zinc chloride in china dish. Now add this powder ZnCl2 into the molten mass during the course of ten minutes using constant stirring. Transfer this solid in china dish and add 20 ml water and 1 ml conc. HCl and boil for 10 minutes. In this way the unchanged starting materials and the basic zinc salt are dissolved. Separate the fluorescein from the aqueous liquid by filtration, wash with water until the filtrate is no longer acid. Dissolve a particle of the preparation in a little ammonia and dilute in a beaker with one liter of water. Determine the weight and melting point of the solid. Calculate the % yield of the product. Obtain and interpret an infrared spectrum of the Then add 0.8g NaOH to the cold Alclorite solution. Cool the NaOH/Alclorite solution to -10°C in the freezer. Grind 1.5 g phthalimide to a fine powder. Now add this to the cold (-10°C) Alclorite solution, plug the flask and mix with magnetic stirrer (or shake). The phthalimide will dissolve within 5 minutes. Place in the freezer again for at least 30 minutes. Now add the cold NaOH solution prepared above to the cold (not over +5°C) Alclorite solution. Allow to stand at room temperature until temperature reaches 20°C. Now heat to 80-85°C over 10 minutes and hold there for at least two minutes but not more than five. Cool in water to room temperature. Transfer the solution to a 100 mL beaker, keep some (~2-3 mL) in the Conical flask. Stir at medium speed on a magnetic stirrer. Now add 30% hydrochloric acid drop by drop till pH of the solution become 7 and filter it. Now add about 1.5 mL glacial acetic acid to this reaction mixture. Maintain temperature 200C or below and stir it. The anthranilic acid precipitated. Filter and dry it. Determine the weight and melting point of the solid. Calculate the % yield of the
Each subsequent trial will use one gram more. 2.Put baking soda into reaction vessel. 3.Measure 40 mL vinegar. 4.Completely fill 1000 mL graduated cylinder with water.
Place a clean, dry 125 mL Erlenmeyer flask on balance, and slowly dispense liquid bleach until there is about .5 g. Record the mass of bleach, and add 25 mL of de-ionized water and about 2 g of KI. Swirl contents until the KI dissolves. Then add 3 drops of 1 M H2SO4, mix, and let stand for 1 or 2 minutes.
Switch to a solution of 1 part water to 1 part ammonia or 1 part water to 1 part hydrogen peroxide....
neutralize 35ml of our base. Once we weighed out the KHP we then dissolved it
To continue this experiment further, I could use frozen chopped spinach leaves, or substitute the rubbing alcohol for methyl alcohol.
Then the reaction tube was capped but not tightly. The tube then was placed in a sand bath reflux to heat it until a brown color was formed. Then the tube was taken out of the sand bath and allowed to cool to room temperature. Then the tube was shaken until a formation of a white solid at the bottom of the tube. After formation of the white solid, diphenyl ether (2 mL) was added to the solution and heated until the white solid was completely dissolved in the solution. After heating, the tube was cooled to room temperature. Then toluene (2 mL) was added to the solution. The tube was then placed in an ice bath. Then the solution was filtered via vacuum filtration, and there was a formation of a white solid. Then the product was dried and weighed. The Final product was hexaphenylbenzene (0.094 g, 0.176 mmol,
Next, repeat steps 7-11 4 times however this time you don’t do it with hot water you do it with the cold water. To keep the cold water cold put ice cubes in the water if it starts to become warm. 14.
Add aluminum amalgam in to acetic acid with water and mix. Wait for about 3-5 minutes, while solution will turn grey. Then add P2NP solution and wait 5-10 minutes while stormy reaction starts. Let the flask to stay for about 20-25 minutes.
5.) One at a time, place your test tubes in the water bath and heat the first test tube to 25 , the second to 50 , the third to 75, and the last to 100 degrees c. Remeber to stir with your stirring rod every so often.
The procedure for this experiment can be found in Inorganic Chemistry Lab Manual prepared by Dr. Virgil Payne.
In a 100ml beaker place 50mls of water, measure the temperature of the water and record this initial temperature onto a table. Set the timer and add one teaspoon of Ammonium Nitrate to the water, stir this continuously until the Ammonium Nitrate has dissolved.
A condenser and heat reflux was used to prevent reagents from escaping. Then the solid product was vacuum filtered. The product was recrystallized to purify it and the unknown
9. When all magnesium has reacted, remove the lid and heat strongly for 5 minutes
2nd step heat the mixture: Make sure the agarose dissolves. Wait until it boils and when you are going to transfer the mixture, wear gloves to avoid getting burnt. Transfer the mixture into a removable gel tray.
Add 5 g crushed nutmeg and 50 mL hexane-isopropanol into a flask and warm for 15 minutes.