The main goal of this experiment was to analyze the kinetics of the reduction of hexacyanoferrate(III) by ascorbic acid. This reaction mechanism should theoretically produce a graph indicating a second-order reaction. The first step of the experiment was to derive and integrate the rate equation from the proposed mechanism. The results of this derivation can be found in the introduction section of the lab report. For the actual experiment, several absorbance and concentration values were obtained directly from the UV-Vis data and/or calculated using that data. The initial absorbance and concentration of Fe(CN)63- (at zero time) was (0.545 +/- 0.003) and (0.000538 +/- +/- 3X10-6) M, respectively. The initial concentration, …show more content…
This reaction displays second order kinetics according to the proposed mechanism. From the mechanism (Curotto 100) a rate equation can be derived. To find the rate law of the reaction, the following derivative must be found. (Equation 2) According to Equation 5, the slope of the line is equal to the negative value of the rate constant, k. The complete derivation and integration of the rate equation can be found on pages 85-88 of the lab notebook. Method According to the lab manual, a spec 20 was to be used to obtain the absorbance values. Instead, the UV-Vis instrument was used to collect the absorbance data for the four solutions. The first step for this experiment was to zero the instrument, and an initial Fe(CN)63- solution was run for about two minutes to obtain the zero-time absorbance and concentration values. The next step was to calculate the masses/volumes needed to make the necessary stock solutions. These calculations for the mass and/or volume needed to make these solutions can be found on pages 78-83 of the lab notebook. Table 1 contains a list of the stock solutions, the concentrations (theoretical and experimental), and the
The goal of this two week lab was to examine the stereochemistry of the oxidation-reduction interconversion of 4-tert-butylcyclohexanol and 4-tert-butylcyclohexanone. The purpose of first week was to explore the oxidation of an alcohol to a ketone and see how the reduction of the ketone will affect the stereoselectivity. The purpose of first week is to oxidize the alcohol, 4-tert-butylcyclohexanol, to ketone just so that it can be reduced back into the alcohol to see how OH will react. The purpose of second week was to reduce 4-tert-butylcyclohexanol from first week and determine the effect of the product's diastereoselectivity by performing reduction procedures using sodium borohydride The chemicals for this lab are sodium hypochlorite, 4-tert-butylcyclohexanone
Felder, M. Richard, Elementary Principles of Chemical Processes, 3rd ed.; Wiley: New Jersey, 2000; p 631.
We were then to make a base solution of 0.7 M NaOH. In order to standardize
Experimental: The experimental procedure outlined in the OU Physical Chemistry Laboratory Manual was followed without any deviations.
1. Read through the steps in this procedure. Prepare a data table to record the mass of the solute, the initial volume of water, the total volume of water after step 9, and the temperatures at which the solutions began to crystallize.
We’d note down the weight. Then we’d get our solutions ready. We were only given a 100% solution and a 0% solution, so we had to mix them in the right ratio to get all the solutions we needed. We decided to do 5 different types of solutions so we would have a wide range of results and it would be more accurate. We’d use 100%, 75%, 50%, 25%, 0% solutions in our experiment.
Start to prepare the sample in a 10mL (10000µm) place 0.4mL (400µm) of the stock Ferritin solution 0.5g/mL in 0.15M sodium acetate (AcONa). Afterwards add 0.8mL (800µm) at 2M of sulphuric acid (H₂SO₄) and 0.8mL (800µm) at 5mM of dihydroxyfumarate (C₄H₄O₆). Wait for 30 minutes then complement the solution with 1.6mL (1600µm) at 2.5M of sodium acetate (NaOAc) followed by 0.8mL (800µm) at 12.5mM ferrozine (C20H12N4Na2O6S2). Lastly wait another 30 minutes afterwards add distilled water using a stopper to complete the solution to 10mL (10000µm) then put the rubber stopper on the volumetric flask and mix till you are sure that all the contents are mixed. Again, set up the spectrometer to 562nm and using the 2 samples that were made take one from each to measure the absorbance plus a third one from either one of the solution.
A cuvette was filled 3/ 4ths of the way and the absorbance measured in a spectrophotometer. The data was compiled as a class and recorded. The Spectrophotometer was blanked using a test tube of distilled water.
In this experiment there were eight different equations used and they were, molecular equation, total ionic equation, net ionic equation, calculating the number of moles, calculating the theoretical yield and limiting reagent, calculating the mass of〖PbCrO〗_4, calculating actual yield, calculating percent yield (Lab Guide pg.83-85).
Once the mixture had been completely dissolved, the solution was transferred to a separatory funnel. The solution was then extracted twice using 5.0 mL of 1 M
I ended up starting at 6.4 and use all of it up to 49.0. To make silver nitrate, we used (0.5 mol) *(.250 dm squared) which equals .125, then times .125 by the molar mass which is 169.82 to get 21.2275 grams. From that point, we were able to make the solution of silver nitrate.
Beers Law is the absorbance over concentration(mol/L). The Linear regression for this experiment was Abs = 3.990 X 104 Concentration(M) + .05956 and the reason why the experiment required this linear regression was to determined the rate law. by founding the specific wavelength of the substance being used, in this experiment it will be crystal violet decolorized over a series of Dilutions. Meaning the experimenters first had to have a stock solution and take 10ml of that stock solution to a beaker with 10ml H2O over a series of 5 dilutions. The Colorimeter was used to measure absorbance vs. concentration of crystal violet at specific times, pseudo k, and actual k. These are gathered through logger pro, so the graphs can be formed. In determining the actual k was the use of the “flooding technique” of OH- were the Crystal violet is relative to OH- making the actually k and if the concentration of hydroxide is constant then it becomes a pseudo-order. In the experiment we could have some errors such as not properly cleaning the cuvlette with the kimwhipes and the way to reduce this error is by during after every reaction we
3.) Divide your 30g of white substance into the 4 test tubes evenly. You should put 7.5g into each test tube along with the water.
The aim of this experiment was to investigate the affect of the use of a catalyst and temperature on the rate of reaction while keeping all the other factors that affect the reaction rate constant.
an enzyme is used to speed up the process in the equation above. In my