In Part A of an experiment, you made a mixture with a large excess of Fe3+ and then assumed that the SCN- was essentially “used up” in the reaction. Using the average K value reported below, evaluate the validity of this assumption. Part A Data:
Volume of 0.20 M Fe(NO3)3 solution: 18.01 mL
Volume of 3.0 x 10-3 M KSCN solution: 1.00 mL
Reported K Value: 120±20

1) Calculate the molarity of SCN- ions that are actually present at equilibrium in the mixture in Part A.

2) Calculate the percentage of the SCN- ion that did not react in this mixture.
%ofSCN-=[SCN- at equilibrium] / initial[SCN-] * 100%

3) Based on your calculations, can we confirm that all of the SCN- reacted with Fe3+ in Part A? Explain.