Throughout the mixing process, the clear red solution slowly changes to a denser red solution (Appendix figure 23). A thermometer was used for temperature checking. The beaker was removed from the hot plate when the temperature was found to be higher than 50 ℃. This was done to prevent a sudden gelation happen before all the active dissolved in the ethylene glycol. Moderate heating of the solution for a period of time is allowed to obtain a wet gel (Appendix figure 24).
After completion of the solubility tests, the appropriate solvent, cyclohexane, was selected for large-scale recrystallization. The unknown was weighed for the large-scale recrystallization then the same process was repeated to test the solubility. The solute dissolved after adding of about 60 mL of solvent, it was set aside to cool to induce crystal reformation. The solution was then seeded and set alone once more. When the process was complete, the crystals
The mixture was placed in a water bath (90ºC) for 10 minutes to allow the reaction to be completed. After the reaction has being completed, the test tube was removed and allowed to be cooled. The alcohol (methyl alcohol) loses OH while the carboxylic acid (salicyclic acid) loses a H. The method which is used in this experiment is only suitable for preparing small amounts of ester. The ester which is formed also can only be categorized by odour. After it has cooled, the fumes was carefully walf by passing our hand over the top of the tube towards our
Extraction of Crude extract Propolis samples were refrigerated about -20c°. after refrigeration the propolis samples were grinded and macerated (30g of propolis, making up the volume to 100 mL with 70% ethanol) and was filtered. The filtrate was evaporated to dryness at 80°C under reduced pressure. 3. Characterization of Crude Extract 3.1 Physical Test 3.1.1 Organoleptic Test The color, odor and physical state of extract will be determined.
Ethylene and the catalyst promoter (HCl) are introduced into the reactor through sparges and effectively all ethylene is converted into ethylbenzene. Low ethylene and high benzene ratios are used in order to give desired yield of ethylbenzene. Most commercial plants operate at the ratio if 0.3-0.35 because as the ratio increased, more side reactions will occur such as transalkylation and isomeric rearrangement. Further alkylation of ethylbenzene will leads to formation of polyalkylbenzenes. The loss in net yield can be recovered by recycling the material to the alkylation
Then, the flask is put on shaker table and mixed at 150 rounds per minute before allowing them to settle for 10 minutes. After settling, the water sample is poured from side spout which is connected to the bottom of the flask. Some researchers reported better reproducibility with modified flask where stopcock is installed at the bottom of the flask, instead of side spout to pour the water sample (Blondina, et al., 1997) (Sorial, et al., 2004a) (Sorial, et al., 2004b). The dispersed oil in the removed water sample is extracted into methylene chloride for further analysis. Then, the oil concentration is evaluated using 340, 370 and 400 nm light absorbance (Environmental Protection Agency,
Ensure that solid is completely dissolved using a stirring rod. Next, a 10 mL beaker is filled with 3 mL of HCl and measure 10 mL of ionized water into a 140 mL beaker. Carefully turn on laboratory burner and start cleaning the Nichrome wire by dipping it into concentrated HCl acid. Hold the Nichrome wire on top of the flame and repeat the step until the wire doesn 't show any color. When the wire is clean, dip the wire again with some of the acid and dip it into the solution with the unknown compound in it.
First, an appropriate amount of TiO2 was added into the methanol (50 mL) taken in the beaker (100 mL) and ultrasonicated for 30 min for complete dispersion of TiO2. After that calculated amount of synthesized g-C3N4 was added into the TiO2 suspension and stirred for 24 h at room atmosphere. After volatilization of the methanol, the obtained solid materials were dried in an oven at 348 K for 12 h. Finally the synthesized g-C3N4/TiO2 nanoparticle and nanotube composite materials with different weight percentage of g-C3N4 loaded were labeled as x%-CN/TNP and x%-CN/TNT (x=1%, 3%, 5%, 7%, and
Added 2 ml of the dissolved sodium hydroxide into the heated oil, immediate the mixture turns cloudy. Set aside to stir for 30 minutes on high. Transfer contents of beaker into a 250 mL separator funnel. Leave the mix to break up for overnight. Transfer the glycerol (bottom layer) into a beaker from
3.5 SOLVENT EXTRACTION PROCESS First, 10g of the RSS were transferred into a thimble. At the same time, 150mL of solvent was poured into the round bottomed flask. Then, Soxhlet were heated using heating mantle. The oil was recovered from the solvent by evaporation of the solvent in a rotary vacuum evaporator under reduced pressure. The mixture of the oil and excess solvent was poured into a weighed round bottomed flask.