Thiocyanate Concentration

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Investigating the Concentration of Iron (III) Thiocyanate Research Question: To determine the optimal effect (equilibrium condition) of manipulating the concentration of both reactants on the values of absorbance detected by a spectrophotometer at 540 nanometers, in between the forward reaction of Iron (III) Chloride (FeCl3) and Potassium Thiocyanate (KSCN). Background Information: I’m an IASAS theatre tech alternate and my main role is being the assistant stage manager, which puts me in charge of handling props as well. It was quite engaging for me to find a reaction that created a chemical replica of hemoglobin; especially after our recent production: The Complete Works of Shakespeare. Thus, it was interesting to find an equal solution…show more content…
DV Color Change This cannot be measured directly, as the color change occurs too quickly to have any actual measurement. However, the color change is measured by measuring the final solution’s absorbance with a Genesys 20 spectrophotometer set at 540 nanometers. Controlled Wavelength of absorption Genesys 20 Spectrophotometer was manually set to a wavelength of 540 nm. I used 540 nm by taking the average of 510 and 570 nm (UV-Visible Spectroscopy) after researching the optimal wavelength to use for a dark red solution. As there was no exact value given, I took the average between the most mentioned intervals. Length of time reaction occurs before measuring Each reaction was allowed 1 minute of reaction time before being placed into cuvettes. (UV-Visible Spectroscopy) Volume of reactants The initial volumes of each reactant was kept constant at 20 cm3 through every manipulation, in order to decrease uncertainty and chances of error. Equipment used Same Spectrophotometer will be used. Method/Procedure: Equipment and Reagent…show more content…
So, we’ll be going from 0.5 to 0.4, 0.3, 0.2, 0.1 mol/dm3 accordingly for each reactant, while the other reactant stays a constant 0.5 mol/dm3. a) For each manipulation, we’ll be conducting 4 trials, so prepare 4 cuvettes and their lids ahead of time. 3) Make sure your gloves, safety goggles and apron are on before proceeding further. Let’s say we’re manipulating concentrations for Iron (III) Chloride and the first manipulation is to react 0.4 mol/dm3 FeCl3 and 0.5 mol/dm3 KSCN. 4) Use a 25 cm3 graduated cylinder for the initial measurements of each solution. Pour 20 cm3 of 0.5M FeCl3 and 20 cm3 of 0.5M KSCN in separate graduated cylinders. 5) Using a 10 cm3 graduated cylinder, pour the necessary volume of distilled water, in this case 5 cm3. After pouring the distilled water to the graduated cylinder containing the FeCl3. 6) Next, prepare a 50 cm3 beaker, and pour both reactants into it. Wait for at least 1 minute to allow the reaction to reach completion. Procedure—Post-dilution 1) Use a pipette to fill 3/4 of each cuvette with the new solution from the beaker. Repeat until you have 4 cuvettes with the same solution. 2) Put a lid on each cuvette in order to prevent

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