To find chemical equilibrium, the following chemical equation is used in the experiment: Fe3+(aq) + SCN-(aq) FeSCN2+(aq). When iron (III) and thiocyanate react, thiocyanoiron (III) is produced. When the concentration of all ions at equilibrium are known, the equilibrium constant can be calculated by dividing the equilibrium concentration of the reactant by the equilibrium concentration of the products. In this experiment, four equilibrium systems containing different concentrations of three different ion types (Fe(NO3)3, KSCN-, and distilled water) are made and used to determine equilibrium concentrations. The equilibrium concentrations are used to calculate the concentration that all of the components of the chemical equation are at equilibrium. Using a colorimeter or spectrometer to determine the equilibrium concentration of FeSCN2+(aq) and …show more content…
Prepare the standard solution of FeSCN2+ pipetting 18 mL of 0.200 M Fe(NO3)3 in a 20 * 150 mm test tube labeled five. Pipet 2 mL 0.0020 M KSCN into the test tube and stir. 6. Prepare a blank. Fill the plastic cuvette ¾ full with distilled H2O. Properly clean the cuvette and handle only by the top ribbed edge while wearing gloves. Dislodge any bubbles by tapping on a hard surface and position the cuvette in the spectrometer so light passes through the clear side. 7. Connect the spectrometer to Labquest and select a new file. Calibrate the spectrometer by placing the blank inside and allowing the lamp to warm up. The optimal wavelength for the standard curve and data collection can be started at this stage. Empty the blank and use the solution from test tube one to rinse the cuvette twice. Fill it ¾ with solution one, wipe the outside, and place it in the spectrometer. 8. Start data collection and display a full spectrum graph. Stop the data and the wavelength of maximum absorbance will be identified. Under the Meter tab, select mode and then events with entry. Type in the name as concentration and the units as