Pour this mixture, while stirring, into a beaker containing 25 mL of ice water to which 5 mL of concentrated hydrochloric acid have been added. The diazonium salt of sulfanilic acid should soon separate as a finely divided white precipitate. Keep this suspension cooled in an ice bath until it is to be used. 2. Methyl Orange 1.
Then, it is air dried and followed by fixing it with flame from Bunsen burner. After fixing the smear, it must be stained using Gram staining solution, firstly crystal violet solution was flood onto it, and allowed for 1 minute, then wash off with tap water. Then, flood the slide with iodine solution for 1 minute and wash it off with tap water again. The formation of a dye-iodine complex will occur in the cytoplasm. Then, it was flooded with ethanol and washed immediately.
22.5 g of plate count agar powder was dissolved in a litre of sterile distilled water on the hot plate 2. pH of the solution was adjusted to 7.0 ± 0.2 by adding NaOH or HCl and was immediately transferred into the Schott bottle to be autoclaved at 121 ° C for 15 minutes 3. Prepared medium was stored in 4° C chiller Lauryl Sulphate Broth
The solution was then seeded and set alone once more. When the process was complete, the crystals
Upon finding the actual concentrations of salicylic acid, concentration of aspirin in the flask at various times can be found using the equation [aspirin]t = [aspirin]0 – [salicylic acid], since at constant volume, number of moles of initial aspirin decrease to form salicylic acid. Initial concentration of aspirin formed as follows: [aspirin]0 = 0.212g / (180.157gmol-1 * 50/1000 L) = 0.0235 mol L-1.
1 “substrate” and another “ enzyme.” Instead of using the distilled water, this time you are going to use different pH buffer in the enzyme test tube. In the substrate tube, add 7 mL of distilled water, 0.3 mL of hydrogen peroxide, and 0.2 mL of guaiacol for a total volume of 7.5 mL. For the enzyme tube, instead of distilled water add the pH solution (3) and 1.5 mL of peroxidase which equals a total volume of 7.5 mL. Use the dH2O syringe for our pH solution. To clean the syringe, flush it by drawing 6 mL of distilled water.
Once cool to touch the squeeze out all the tea bags carefully without tearing them apart. Using a separatory funnel extract three times with 15.0ml of dichloromethane gently rocking bath and forth the funnel venting the funnel often each time. Carefully decant into a pre-weighed 125ml flask and add the drying agent-calcium chloride pellets- and the organic layer was evaporated off in a warm water bath. Using aluminum foil as support around the mouth of the flask place test tube in the flask and heat the flask on a hot plate whilst adding water into the tube without letting it boil. Once the caffeine forms crystals around the test tube scrape off all the sublimed product and weigh the dried product 0.1grams of caffeine and had a melting point range of 175-230
V. Results and Discussion One of the objectives of this exercise is to synthesize acetylsalicylic acid (aspirin) from salicylic acid. The mechanism for this synthesis is through nucleophilic acyl substitution. Acetic anhydride was the acetylation reagent used with the salicylic acid. The mechanisms and the reaction involved in the synthesis are seen in the following figure. 1.00 gram of fine white salicylic acid powder was weighed in a clean, dry 125mL Erlenmeyer flask.
The crude caffeine was transferred to Petri dish. Petri dish was placed on a hot plate and covered with three disks of filter paper. Another petri dish filled with ice was placed just on the top of petri dish covered with filter papers. The heat was turned on and sublimation was performed for 5 minutes. The purified caffeine was scraped from the filter papers and its weigh was measured.
The residual biomass was separated by filtration and washed with distilled water. For alginate extraction, the acidified algal biomass was suspended in 3% Na2CO3 solution at different alkali: alga ratio (20, 40, and 60 mL/g). The different extraction temperatures ranged from 25 to 45º C, and lasted for 1 to 3 h. For each experimental run, sodium alginate was collected by filtration and precipitated with absolute ethanol (1:2 v/v). The mixture was maintained at 4º C overnight. The precipitate was collected by vacuum filtration and allowed to dry at room temperature.
10. The solution was then placed under the fume hood for the chloroform to evaporate. 11. Methanol was filled in a test tube and placed into a water bath to heat up. 12
Purpose This experiment is to determine the concentration of the solute copper sulfate pentahydrate, and the unknown solution, by passing different wavelengths of light through each solution. Procedure Weigh out approximately 5g of copper sulfate pentahydrate. Record the mass and place the solute into a 50 mL volumetric flask. Fill half of the flask with distilled water, add the stopper for the flask, and lightly shake the flask, until the copper sulfate pentahydrate fully dissolved.
The objective of this experiment was to create synthesize methyl eugenol from eugenol, dimethyl carbonate, and tetrabutylammonium bromide. To start off the experiment, a heating under reflux apparatus was used and the parts included: a water jacketed condenser, ring stand, tubes, flowing water, 25-mL round bottom flask, heating block, and a hot plate. There were two parts to the water condenser, entry and exit ways for water. The bottom opening was connected to the sink through one tube and the top opening was connected with a loose end, which was needed to get rid of the flowing water. To create the solution needed to synthesize methyl eugenol, approximately 0.200 g of eugenol (note: the measured g was converted to mg for later calculations) was measured, alongside approximately 1.2 g of TBAB and was added to the 25-mL round bottom flask.