It binds with starch so the more starch, the darker the solution was. We also used a blank solution with no starch to set the spectrometer to zero. The spectrometer was used to compare the absorbency of the starch in the control solutions and the non-control solutions over time. Amylase was the last solution added to start the initial breakdown of the starch. Adding it at one minute intervals allowed the students to see how much starch the amylase was actually breaking down over time.
The purpose of this step is to separate the aqueous layer from the organic layer. This gets rid of the K-salts of gallic acid and glucose. The organic layer still contained caffeine and chlorophyll and any other organic compounds. The final step is to purify the caffeine from any impurities. Sublimation is the technique used.
At this point the volume of base used to neutralized the acid can be determined. Phenolphthalein is the indicator which is colorless in an acid but changes to a faint and permanent pink color in base. The purpose of this experiment is to prepare a sample for titration with a base, become familiar with a buret while using proper titration technique in reaching an end point. Hypothesis : If I titrate a base of known concentration with an acid of unknown concentration then I can determine the concentration can be calculated because of the titration calculation. Materials : • Vinegar • Two small beakers (150mL) • 250-mL Erlenmeyer flask • 10-mL graduated cylinder • 50-mL buret • Buret clamp • Small funnel • M NaOH Hazards : • Chemical spill • Broken glass
What is a peroxide killer? After bleaching the cellulosic fiber with hydrogen peroxide, the fiber is subjected a thorough hot wash cold wash and neutralization processes. These operations would remove all superficially available chemicals that were used in bleaching process. However in practice it is found that the core alkali i.e. the alkali due to the use of caustic soda or soda ash and hydrogen peroxide, wetting agents and other auxiliaries would remain in the core of the fiber processed even after 2 or 3 washes.
Tissue Papers Absorb Less Liquid in Volume When Concentration of Salt Increases This study was done in an effort to find out the minimum number of papers needed to wipe up a spill so that anyone could prevent wasting paper. In this investigation, sheets of tissue papers were dipped into salt water with different concentrations and soaked until the water traveled to the top, then the amount of water a paper absorbed in terms of both the mass and the volume was recorded. The result showed a strong, positive linear relationship between mass absorbed and salt concentrations, while it showed a slight decrease in volume absorbed with increasing salt concentrations. Further researches could be done to change the substances or even mix different solvents
Three tests will then be performed to examine the identity and purity of the synthesized aspirin. The first test will detect the presence of leftover salicylic acid in the synthesized aspirin. The second test uses melting point to evaluate the purity of the aspirin product. A compound that contains impurities will tend to melt over a range of temperatures and at temperatures lower than the fixed mp for the pure compound. 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.
Athena Cochinamogulos Dr. Miller Organic Chemistry II October 23, 13 Title: Suzuki Palladium Cross-Coupling Reaction: Synthesis of 4-Acetyl-4-methyldiphenyl Abstract: In this experiment, the Suzuki Cross coupling reaction between 4-methylphenylboronic acid and 4-bromoacetophenone was utilized to prepare 1-(4’methyl-biphenyl-4-yl) ethanone. Purification through vacuum filtration was carried out and rotary evaporation was executed. The characterization of the purified product was determined by comparing its spectra and melting points to those presented in the literature. The melting point of the product was 58-70°C; which largely differs from the literature value suggesting impurities but the use of spectra data allowed for the determination of product and overall experimental successful. Reaction Equation: Introduction: An organic reaction of an aryl- or vinyl-boronic acid with an aryl- or vinyl-halide catalyzed by a palladium (0) complex or by a palladium nanomaterial-based catalyst describes the Suzuki reaction first reported by Miyaura, Yanagi, and Suzuki in 1981.
Traditionally stones, also sterilized by boiling, are placed on top of the cucumbers to keep them under the water. The more salt is added the more sour the cucumbers become. Since they are produced without vinegar, a film of bacteria forms on the top, but this does not indicate they have spoiled, and the film is simply removed. They do not, however, keep as long as cucumbers pickled with vinegar, and usually must be refrigerated. Some commercial manufacturers add vinegar as a
In cold climates, a dryer is usually required to dehydrate the gas stream. The gas dryer, sometimes, is also necessary in warmer climates as well. Some gas dryers work at low compression pressure. To remove water vapors to extremely low levels, the molecular sieve adsorbent desiccants are used for gas dryers with low pressure. After a certain period of operations desiccants are required to be repaired or completely replaced by a new one as they have absorbed a huge amount of water contents in them and functioning capacity will be decreased, if not replaced.
Of course the saturated solutions take time this experiment is done in a two day lab setting part one should be completed during the first day and ready for use on day two. Remember because Le Châtelier’s principle if you don’t filter the solution will rise. The removal of OH- from the UN filtered solution will cause more Ca(OH)2 to be dissolved for the equilibrium to restore. The second part of this lab takes knowledge from past experiments done in this laboratory. Using the Primary method used to standardize the concentration of HCl, this will bring much lower percent error in the Ksp For this standardization sodium carbonate should be used for determining the amount of hydroxide in the solution.