Water will act as initial solvent for caffeine extraction. This is due to water that slowly soluble with caffeine at ambient temperature but highly soluble when temperature is at 100°C. Then, methylene chloride is chosen as the extraction solvent, due to its miscibility with caffeine and immiscibility with water. As mentioned above, the immiscible pair is chose for the extraction part because to allow the aqueous and organic layers to be separated. Basically, the bottom layer is the aqueous layer while the upper layer is the organic compound.
Water acts as a leaving group in the third step and is removed from the reaction intermediate. In the fourth step, the molecule undergoes deprotonation with the help of the concentrated sulfuric acid to form isopentyl acetate. The reaction that was carried out in the experiment was a reversible reaction. In order to obtain as much isopentyl acetate as possible, Le Chatelier’s principle was used to ensure that we were able to collect a sufficient amount of isopentyl acetate. Le Chatelier’s principle says that if you disturb a system in equilibrium the equilibrium will shift in order to account for the disturbance.
Pyruvate can be metabolized into neutral compounds such as acetoin, 2-3 butylene glycol, and diacetyl. [2 pyruvate -> acetoin + 2CO2 ; acetoin + NADH + H+ -> 2,3-butanediol + NAD+] “In the presence of alkali (KOH) and atmospheric oxygen, acetyl methyl carbinol is oxidized to diacetyl, a reaction which is catalyzed by alpha- naphthol. Diacetyl formed reacts with guanidine-containing compounds such as arginine contributed by peptone in the medium, to form a red colored product. The resultant red color is indicative of a positive VP test.” (Pradhan, 2014) In both cultures, there is no red coloration observed (see Figure 11.6 and 11.7), thus Micrococcus luteus and the unknown microbe are both unable to produce acetoin via butanediol
Screening to separate the large contaminants from the water b. Coagulation to attract small contaminants c. Sedimentation where water sits and finishes coagulation d. Filtration to remove any small remaining contaminants and particles e. Disinfection by disinfecting chemicals such as chlorine to kill microorganism or remaining bacteria 2. Explain the differences between primary, secondary, and tertiary sewage treatment. a.
Xylene should be dried because it will be removed from the product. A drying tube with calcium chloride was used for the reaction during the set up because it will remove and catch specific compounds leaving the reaction or being produced from the reaction. The purification method is by using adding petroleum ether to produce crystals and then vacuum filtration to remove the crystals from the solution. The melting point for 4-cyclohexene-cis-1,2-dicarboxylic anhydride as a pure compound is measured at approximately 97-103ºC. The measured melting point from the experiment is approximately 70-80ºC.
This fluid then flows into the loop of Henle and to the collecting ducts. Substances are removed through diffusion, active transport, and osmosis. The filtered substances go into the renal veins and back into the circulatory system. Third Step: Tubular Secretion. This process helps to eliminate toxins from the body.
The purpose of this experiment was to synthesize a Grignard reagent with 1-bromobutane and homogenized magnesium in anhydrous diethyl ether. This solution was refluxed in a flask connected to condenser and drying tube. As seen in the mechanism, maintaining a dry condition is important to avoid the Grignard reagent from attacking water, which will result in loss of the bromine. It is important to reduce the amount of moisture and water vapors to avoid destroying the Grignard reagent, which is essential to the synthesis of 2-methylhexanol. Hence, a calcium chloride and cotton were filled inside a drying tube.
In the second step, the addition of sodium borohydride reduced the imine into another derivative, which was yellowish lime color. The solution turned clear when acids and anhydrides was added, which indicated the precipitate were dissolved. However, after refluxing for a while, yellow precipitates begin to form near the top of the flask. It was assumed that the remaining starting material was concentrated from a decrease volume to reappeared in solution. Nevertheless, this may have been a sign of contamination that will negatively affect the entire reaction.
It is secreted by type II alveolar cells, which secrete alveolar fluid (surfactant is a component of alveolar fluid). Surfactant is a mixture of phospholipids and lipoproteins, which serves to lower the surface tension of alveolar fluid, 30 preventing collapse of alveoli and maintaining their patency 8. Meconium, when aspirated into the lungs, deactivates surfactant. Research has also shown that meconium disturbs surfactant synthesis, with a study concluding that surfactant phosphatidylcholine (a phospholipoprotein which forms about 85% of the lipid component in surfactant) concentrations are low in infants with meconium aspiration syndrome 14. In addition, another study has demonstrated the surfactant-stripping effect of meconium, due to the high minimum surface tensions of the major free fatty acids of meconium (palmitic, stearic, and oleic acids) 15,16.
Sodium azide (NaN3) decomposes at 300oC which produces sodium (Na) and nitrogen gas (N2). The nitrogen that is generated then fills the airbag. The purpose of the KNO3 and SiO2 is to remove the sodium (N2) which is highly explosive and dangerous metao, by converting it to a harmless material. Secondly, the sodium reacts with potassium nitrate (KNO3) to produce potassium oxide (K2O), sodium oxide (Na2O), and additional nitrogen gas. The N2 generated in this second reaction also fills the airbag, and the metal oxides react with silicon dioxide (SiO2) in a final reaction to produce silicate glass, which is harmless and stable; Chemistry.wustl.edu, (2000).