Using a measuring cylinder, add 50cm3 of 1.0mol dm-3 sulphuric(VI) acid to the thyme extract in the conical flask. 8. Titrate the solution in the conical flask with the potassium manganate(VII) solution until a pale pink colour persists for 10 seconds. 9. Repeat the titration until there are two titres within 0.1cm3 of each other.
After the effervescence, (15mL) of concentrated HCl was added drop wise to the solution. The mixture was then heated for 15 minutes in a boiling water bath. In two separate small beakers (20mL) of distilled water was placed in one and (20mL) of 6M HCl in the other. Both beakers were placed into an ice bath. After heating, the mixture was cooled to room temperature and filtered by vacuum filtration into a fritted funnel to yield a purple product.
For a single extraction, use a 50mL graduated cylinder and measure out 50mL of the benzoic acid solution into a 125mL separatory funnel. Add 10mL of methylene chloride (dichloromethane or CH2Cl2 for abbreviation which is the organic layer), the extracting solvent, to the funnel. Shake the funnel for thirty seconds pointing it away from the student and self. Release gas buildup by opening the stopcock of the separatory funnel. This is called the shaking and venting procedure.
The mixture was refluxed to avoid evaporation while it boiled for 30 minutes. After 30 minutes the mixture was cooled and then filtered through fluted filter paper into a 250ml round bottom flask. The methyene chloride dissolved the trimystrin and would pass through the filter paper leaving the other nutmeg solids behind. The solution was then distilled to get rid of the methlyene chloride and isolate the trimyristin. Methlyene chloride was a good solvent in this case because its boiling point is 40 degrees C and will boil off before the trimyristin which has a boiling point of 56-57 degrees C. Finally acetone was added to wash the crystals and the solution was vacuum filtered.
This solution was added drop wise to the stirred ethanolic solution of benzophenone at room temperature. After all the sodium borohydride being added, the mixture was stirred for a further 10min. Meanwhile, ice water (10ml) was mixed with concentrated hydrochloric acid (1ml) in 50ml beaker. To this the mixture of sodium borohydride and benzophenone was poured slowly into the beaker. The precipitate was collected using suction filtration and washed with 2 x 5ml portions of water.
The third test will utilize thin layer chromatography to evaluate the purity of the aspirin as well as testing for the presence of leftover salicylic acid or other by products of the reactions. Experimental: Week 1: For the synthesis of the aspirin, 250 mL of water was boiled. 1.5 g. of salicylic acid were poured on a test tube. Then, 3.5 mL of acetic anhydride and four drops of 85% phosphoric acid were added. A cotton ball was placed to prevent vapor escape.
Procedure: Fill a buret and tip with KMnO4. Place approximately 1g of iron (ii) ammonium sulfate hexahydrate in a weighing boat and mass with an analytical balance to +/- 0.0001g. Transfer the FAS to an Erlenmeyer flask. Add 25mLof distilled water, 15mL of 3M H2SO4 to the flask and swirl to dissolve the FAS. Place about 50mL of water in a beaker and 1 drop of the permanganate solution for the color constant.
This lab exercise focuses attention on the former reaction. Lipid oxidation, which is also called auto-oxidation, occurs in lipid material by way of a free-radical mechanism. After an induction period, hydrogen peroxides, or primary products, are formed. Ultimately these peroxides break down, and secondary products, e.g., aldehydes, ketones, organic acids, and hydrocarbons, are formed. The peroxide value (PV) test, which is one of the most common tests used to evaluate the extent of lipid oxidation, is based on measuring peroxides.
The extraction process is when a solvent, dichloromethane (15mL) is added to the filtrate in a separatory funnel; the mixture is gently swirled together 3 times, and stopcock is released in between to vent the funnel. Dichloromethane (including the emulsion) is then drained from the bottom into a 50mL Erlenmeyer flask. Same extraction process is repeated on the same filtrate and the dichloromethane is, once again, let out to the same 50mL Erlenmeyer flask as before. The combined dichloromethane solution and water (20mL) is poured into a rinsed separatory funnel. Mixture is gently swirled and drained out into an Erlenmeyer flask.
When using Benedict’s reagent, monosaccharides can be identified. Benedict’s reacts with double bonds connected to the oxygen atom in either the free ketone or aldehyde groups (which are the reducing sugars in saccharides) to reduce the copper sulfate in Benedict’s reagent (Harris-Haller 2014). When the substance is heated with Benedict’s reagent, an orange-red precipitate forms within the solution. There were 10 substances in all that we tested for. They were glucose, water, lemon juice, Coca Cola, egg batter, lemon-lime soda, diet lemon-lime soda, Kraft Italian dressing, skim milk and butter.