DATA AND CALCULATIONS K0expressionK0=[FeSCN2+][Fe3t][SCN] Average of Kc values Kc= at Sample Calculations to be done on the next page. Experiment 5 Sample Calculations PROCESSING THE DATA Chemical Equilibrium: Finding a 1. Write the Ke expression for the reaction in the Data and Calculation table. 2. Calculate the initial concentration of Fe34, based on the dilution that results from adding KSCN solution and water to the original 0.0020MFe(NO3)3 solution. See Step 2 of the procedure for the volume of each substance used in Trials 1-4. Calculate [Fe3+]i using the equation: [Fe1]i=x(0.0020M) This should be the same for all four test tubes. 3. Calculate the initial concentration of SCN, based on its dilution by Fe(NO3)3 and water: [SCN]i=x(0.0020M) In Test Tube 1,[SCN]i=(2mL/10mL)(.0020M)=.00040M. Calculate this for the other three test tubes. 4. [FeSCN2+]eq is calculated using the formula: [FeSCN2+]eq=x[FeSCN2+]std where Aeq and Astd are the absorbance values for the equilibrium and standard test tubes, respectively, and [FeSCN2+]std=(1/10)(0.0020)=0.00020M. Recall that [FeSCN+]std is assumed to be equal to [SCN]i. Calculate [FeSCN2+]eq for each of the four trials. 5. [Fe3+]eq: Calculate the concentration of Fe3+ at equilibrium for Trials 14 using the equation: [Fe3+]eq=[Fe3+]i[FeSCN2+]eq 6. [SCN]cq : Calculate the concentration of SCNat equilibrium for Trials 14 using the equation: [SCN]eq=[SCN]i[FeSCN2+]eq 7. Calculate Kc for Trials 1-4. Be sure to show the Kc expression and the values substituted in for each of these calculations. 8. Using your four calculated Kc values, determine an average value for Ke. How constant were your Kc values