Hexacyanoferrate Reaction Lab Report

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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

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