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Category : Natural Sciences

Synthesis and Characterization of Aspirin

Purpose The purpose of this lab was to synthesize Aspirin and measure the synthesized Aspirin’s purity. By calculating the theoretical yield based on the original amount of Salicylic acid, one could determine the actual yield percentage of the reaction. By measuring the melting point of the synthesized substance as well as taking a UV spectroscopy, it is then possible to measure the purity of the synthesized compound as well. With the yield percentage and the purity of the product, one […]

Determining the Equilibrium Constant of Bromothymol Blue

Written by Lisa Abstract Bromothymol blue is an indicator used to detect weak acids and bases.  In acidic solutions, it appears yellow, in basic solutions it is blue, and in mid pH ranges, it is green.  By determining the absorbance values of solutions at all of these extremes, the equilibrium constant (Kc) of this indicator can be calculated.  After taking the spectra of each the yellow, the blue and the green solutions, a Kc value of (1.2 ± 0.19) M and […]

Separating Fluorine and 9-fluroenone with TLC and Column Chromatography

Written by Alex Discussion: In this lab, both column chromatography and TLC chromotography were used to separate a mixture of fluorine and 9-fluroenone and detect their separation.  In the first part of the experiment, a proper solvent was experimentally found. Through process of elimination, the best solvent for the flourene/fluroenone mixture was found one at a time by performing a TLC chromatography with each solvent.  This is done by spotting a TLC plate on a line penciled in 1cm from […]

Adsorption of Aqueous Acetic Acid onto Activated Charcoal

Written by Javon Results and Discussion             The results were obtained by the collaborators who performed the experiment. Figure 1: c/N vs c Table 1: c/N vs c c c/N 0.00342342 3.00598832 0.01837836 15.831308 0.04160156 22.6250274 0.06804798 30.7722158 0.09537528 38.5146221 0.12260248 4.45704831   Using the equation c/N = c/Nm + 1/kNm, Nm (number of moles of acetic acid required to forma monolayer onto the charcoal) can be approximated as the inverse of the slope of the best fit line. The […]

Comparing Tris-2,2’-bipyridine Complexes of Iron (II) and Ruthenium (II) through Spectroscopy and Electrochemistry

Written by Johanna ABSTRACT: This experiment effectively determined the differences between Iron (II) and Ruthenium (II) Tris-2,2’-bipyridine complexes through the comparison of absorption and emission spectroscopy and cyclic voltammetry.  In both the UV/Vis absorption and emission spectra, the Ru (II) complex shows far greater molar absorptivity values and fluorescence.  The iron complex does not fluoresce.  The MLCT peaks in the UV/Vis spectra correspond to the energy of the t2g à t2g*  or HOMO à LUMO transitions, 2.64 x 105 J/mol […]

Multi-step Synthesis of Ketal Ester

Written by Jimmy Table of 1H NMR Spectral Data of Ketal ester  Table of 13C NMR Spectral Data of Ketal ester        Table of IR Spectral Data of Ketal ester   Provide your experimental index of refraction and correction factor: 1.4229 @ 22ºC 1.4229+0.00045*2=1.4238   Literature=1.4377   Reproduce your Theoretical and Percent Yield Calculations. Ethyl Acetoacetate: 10.0 mL (1.029g/mL) (1/130.14g/mol) = 0.0791 mol Glycol:  4.5 mL (1.113g/mL) (1/62.07g/mol) = 0.0807 mol 1:1 ratio of prods to reacts and reacts […]