In this experiment, two alcohols, 1-propanol and 2-propanol, were oxidized through combining each with an excess amount of chromic acid solution. The purpose for conducting this experiment was to determine the reaction rate constant at which aldehydes and ketones formed from the respective oxidation of 1-propanol and 2-propanol. From this value, the half-life of the alcohol during the reaction could be derived. The progress of the reaction was tracked through the color change of the solution through use of a spectrophotometer. The first 6 minutes of absorbance of each alcohol’s oxidation were graphed. The slopes of the graphs were equivalent to the reaction rate constant, k, for each alcohol. It was determined that the k value of 2-propanol …show more content…
A laptop was then turned and connected to a spectrophotometer, via USB, to collect data. The Logger Pro program was opened on the laptop, and “Experiment” was selected. Once “Experiment” was selected, “Data Collection” was chosen, and the means by which the data would be collected was “Time Base.” The “duration” of time for this experiment was selected to be 30 minutes. The rate at which data was collected was ensured to be “1 samples/minute” and “1 minutes/sample.” The data was recorded at a “continuous” rate with “over collection.” Once the proper settings were chosen, “Done” was selected to prepare for recording data. From there, on the top-right corner of the screen, “Configure Spectrophotometer” was chosen, and a wavelength of light at which the data was collected was set at 440.6 nm. The data was collected by measuring “Absorbance vs. Time.” Then “OK” was selected to secure all setting …show more content…
When analyzing the R2 values of Graphs 1 and 2, their respective R2 values of 0.9956 and 0.99062 indicate the regression of each trend line fits the data points extremely well. From these consistent graphs, the k values of 1-propanol and 2-propanol were identified to be 0.5753 per minutes and 0.4662 per minutes, correspondingly. The half-lives of each were then calculated: t1/2 of 1-propanol = 1.2048 minutes; t1/2 of 2-propanol = 1.4868 minutes. These oxidation techniques are not only often used in the organic chemistry lab, but are frequently used in various scientific fields and are even used to create home care products. Ultimately, this particular lab resulted in the collection of very plausible
The cuvette was placed in the spectrophotometer with the arrows, on both the cuvette and the SpectroVis, facing the same side. After the recording, the cuvette was removed from the SpectroVis and the content was poured back into the original volumetric flask. The absorbance as well as the maximum wavelength of each solution was recorded in Table 3 and
That mixture was then filtered through a coffee filter. Nine test tubes were prepared in order to perform this dye coupled reaction. One contained 5.0ml of the potato and pH buffer mixture, 2.0 ml of hydrogen peroxide, and 1.0 of guaiacol to serve as a blank for the spectrophotometer. Four test tubes were filled with 2.0 ml of hydrogen peroxide and 1.0 ml of guaiacol, used for measurement by the spectrophotometer, each. The last four were filled with 4.0 ml of the potato and pH buffer mixture and 1.0 ml of peroxidase.
The reaction was repeated 3 times and average rate noted. From these rates a graph was plotted which describes the relationship of the pressure produced and number of drops added. The reaction rates were measured by Kpa/min and were written to 4 figures for precise results. Time was measured by stop watch. Table 4 shows a summary of all the groups which participated in the lab session.
In this lab, the oxidation of a secondary alcohol was performed and analyzed. An environmentally friendly reagent, sodium hypochlorite, was used to oxidize the alcohol, and an IR spectrum was obtained in order to identify the starting compound and final product. The starting compound could have been one of four alcohols, cyclopentanol, cyclohexanol, 3-heptanol, or 2-heptanol. Since these were the only four initial compounds, the ketone obtained at the end of the experiment could only be one of four products, cyclopentanone, cyclohexanone, 3-heptanone, or 2-heptanone. In order to retrieve one of these ketones, first 1.75g of unknown D was obtained.
When each drop of chemical was carefully squeezed onto the surface of the lab table, the time of evaporation was timed carefully, capturing the exact times each of the substances completely finished evaporation. As a result of this, Acetone evaporated instantly, within just less than a minute, 57 seconds. Propanol and Acetic Acid followed a while afterward, with Propanol evaporating in 8 minutes and 40 seconds and Acetic Acid in 30 minutes and 43 seconds. The distinct and differing times of evaporation of all three chemicals represented the differences in the intermolecular forces that each of the chemicals possesses within their molecules and how they cause each substance to behave when left out to evaporate. Weaker intermolecular forces do not take long to fully evaporate because of the lack of energy required to weaken their bonds, hence Acetone takes less time to evaporate compared to Propanol and Acetic
Set the wavelength to 470 nm, this is to measure the tetraguaiacol. Set the spectrophotometer to zero by using a blank. The blank should contain 13.3 mL of distilled water, 0.2 mL of guaiacol, and 1.5 mL of enzyme extract in a clean test tube. After, transfer a portion of this mixture into a cuvette, cover the top of the cuvette with Parafilm and then place the cuvette into the spectrophotometer and set it to
ABSTRACT To catalyze a reaction, an enzyme will grab on (bind) to one or more reactant molecules. In this experiment we examined how increasing the volume of the extract added to the reaction would affect the rate of the reaction. The enzyme used was horseradish peroxidase which helps catalyze hydrogen peroxide. Using different pH levels, the absorbance rate of the reaction was measured to see at which condition the enzyme worked best. The rates of absorption were calculated using a spectrophotometer in 20 second intervals up to 120 seconds.
Aims of experiment • Determine the rate constants for hydrolysis of (CH3)3CCl in solvent mixtures of different composition (50/50 V/V isopropanol/water and 40/60 V/V isopropanol/water) • Examine the effect of solvent mixture composition on the rate of hydrolysis of (CH3)3CCl Introduction With t-butyl chloride, (CH3)3CCl, being a tertiary halogenoalkane, it is predicted that (CH3)3CCl reacts with water in a nucleophilic substitution reaction (SN1 mechanism), where Step 1 is the rate-determining step. The reaction proceeds in a manner as shown
Record the amount of absorbance by converting transmittance every 5 minutes for a total of 20 minutes. Repeat all of these steps for the cantaloupe, banana, replacing the blank each time to recalibrate the spectrophotometer. After recording all the percent transmittance value, the data was then converted into absorbance value by using the absorbance conversion table. The information was placed on a plotted graph
5 drops of Enzyme color reagent was put into each test tube and then incubated. During the incubation process, the tubes were agitated to evenly mix all the contents in the tube. Following incubation, the spectrophotometer was heated up to prepare for sample readings. Each tube was then dragged into the spectrophotometer to be analyzed. A data point for each analyzed tube was placed on the graph to show the optical density and glucose concentrations.
Background Information: The spectrophotometer is an
Use these results to determine the product concentration, using Beer-Lambert’s Law: A= ɛCl (where A is the absorbance, ɛ is the molar absorptivity, C is the product concentration and l is the length of solution that the light passes through). Calculate the product concentrations at every minute for 10 minutes for all 7 of the test tubes using Beer-Lambert’s Law. Plot a graph of product concentration vs. time and then use the gradients of the 7 test tubes to determine the velocities of the reaction. After calculating the velocities, plot a Michaelis-Menten graph of velocity vs. substrate concentration.
Decomposition of Aspirin Studied with UV/Visible Absorption Spectroscopy Aims: To determine the concentration of salicylic acid, formed from the hydrolysis of Aspirin, at regular intervals using the UV/Visible Absorption Spectroscopy From the concentration of salicylic acid, concentration of Aspirin to be determined using an equation Calculate the rate constant of this reaction and its order from a plot of graph of ln(aspirin) vs time Discuss the overall flaws and improvements to the experiment Results: As per schedule1, 0.212g of aspirin was added to 50 ml boiling water to form salicylic acid in a 100 ml flask, of which 1 ml was then pipetted to a 50 ml volumetric flask at the 5th min. Following an ice bath, the solution was mixed
Introduction Strong acids and strong acids both dissociate completely in water forming ions. However, strong acids donate a proton to form H3O+ along with a conjugate base and strong bases accept a proton to form OH- along with a conjugate acid. The chemical behavior of acids and bases are opposite. When they are together, their ions cancel out and form a neutral solution. In this experiment, HCl and NaOH will react to form NaOH and H2O with these two steps: The overall reaction is: Both Na+ and Cl- ions combine to form NaCl.
It was calculated and found that the concentration of benzoic acid was higher at 30℃ (0.0308M) than at 20℃