Essay on Lab Report On Reagent Contamination

1332 Words Oct 28th, 2016 6 Pages
Overall the experiment provided significant data, despite problems with reagent contamination. Iron (III)-thiocyanate complexes in equilibrium, meaning that external and internal forces on the equilibrium can shift toward the reactants or the complex. External forces are changes to the chemical or physical environment that effect the equilibrium. Internal forces are changes to the bonds or chemical nature of the complex itself. These effects are used to study the optimal chromogenic reagent, meaning that any changes to the system should not change the performance of the chromogenic agent. The chromogenic reagent is the iron(III)-thiocyanate complex.
Time Duration: The maximum wavelength of the complex was found to be approximately 470 nm. Since the complex had a reddish-brown color and the use of complementary colors, the measured absorbance was within the expected value for the visible blue region. For the time duration, physical observation of the samples showed a fading in the color of the complex as time progressed.
As shown to the right in Figure 5, as time progresses there is a steady decrease in absorbance of the complex. This further shows, the limitations of the complex for actual analysis. If one’s goal is to determine the concentration of one reactant, it is highly dependent on time. Meaning that as time progresses, the equilibrium shifts to the left and color fades. Simple quantitative concepts such as Beer’s law would not be applicable. The rapid conversion…

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