Determination Of Keq For FeSCN
The Determination of Keq for FeSCN2+
Joy Muthami
February 12 2014
Introduction:
The purpose of this lab was to calculate the equilibrium constant for the reaction of iron (III) ions with thiocyanate ions. The materials were first acquired then with the groups in the class each team was given a test solution to create and acquire information from then all the information was put together in order to save time. Specifically the group created test solutions #8, #9, and #10. Once the solutions were created, they were stirred to ensure that the reaction had fully occurred. Then the solutions were placed in a spectrometer that was set to a wavelength of 450nm. The absorption for each of the solutions was measured and recorded. With the whole data collected from the overall group a calibration curve was created from the reference solutions and the concentrations of FeSCN2+ at equilibrium was demined by finding the absorbance from the test solutions on the calibration curve and tracing it to their concentrations. The initial concentrations of Fe3+ and SCN- were found using the M1V1 = M2V2 equation along with the concentration of FeSCN2+ used in the calibration curve. Then using the chart that organizes the initial, change, and equilibrium concentrations of a specific products and reactions; the concentration of Fe3+ and SCN- was determined. With the concentrations of the products and the reactants the Keq was determined.
The concepts of chemical equilibrium, equilibrium constant, complex-ion reactions, and spectrometry were used in this lab.
Data Analysis:
Test Solution #6
[Fe3+]*
[SCN-]*
[FeSCN2+]
Initial
0.0010
0.00020
0
Change
-2.2 x 10-5
-2.2 x 10-5
+2.2 x 10-5
Equilibrium
0.000978
0.000178
2.2 x 10-5
Test Solution #7
[Fe3+]*
[SCN-]*
[FeSCN2+]
Initial
0.0010
0.00040
0
Change
-4.7 x 10-5
-4.7 x 10-5
+4.7 x 10-5
Equilibrium
0.000953
0.000353
4.7 x 10-5
Test Solution #8
[Fe3+]*
[SCN-]*
[FeSCN2+]
Initial
0.0010
0.00060
0
Change
-6.8 x 10-5
-6.8 x 10-5
+6.8 x 10-5
Joy Muthami
February 12 2014
Introduction:
The purpose of this lab was to calculate the equilibrium constant for the reaction of iron (III) ions with thiocyanate ions. The materials were first acquired then with the groups in the class each team was given a test solution to create and acquire information from then all the information was put together in order to save time. Specifically the group created test solutions #8, #9, and #10. Once the solutions were created, they were stirred to ensure that the reaction had fully occurred. Then the solutions were placed in a spectrometer that was set to a wavelength of 450nm. The absorption for each of the solutions was measured and recorded. With the whole data collected from the overall group a calibration curve was created from the reference solutions and the concentrations of FeSCN2+ at equilibrium was demined by finding the absorbance from the test solutions on the calibration curve and tracing it to their concentrations. The initial concentrations of Fe3+ and SCN- were found using the M1V1 = M2V2 equation along with the concentration of FeSCN2+ used in the calibration curve. Then using the chart that organizes the initial, change, and equilibrium concentrations of a specific products and reactions; the concentration of Fe3+ and SCN- was determined. With the concentrations of the products and the reactants the Keq was determined.
The concepts of chemical equilibrium, equilibrium constant, complex-ion reactions, and spectrometry were used in this lab.
Data Analysis:
Test Solution #6
[Fe3+]*
[SCN-]*
[FeSCN2+]
Initial
0.0010
0.00020
0
Change
-2.2 x 10-5
-2.2 x 10-5
+2.2 x 10-5
Equilibrium
0.000978
0.000178
2.2 x 10-5
Test Solution #7
[Fe3+]*
[SCN-]*
[FeSCN2+]
Initial
0.0010
0.00040
0
Change
-4.7 x 10-5
-4.7 x 10-5
+4.7 x 10-5
Equilibrium
0.000953
0.000353
4.7 x 10-5
Test Solution #8
[Fe3+]*
[SCN-]*
[FeSCN2+]
Initial
0.0010
0.00060
0
Change
-6.8 x 10-5
-6.8 x 10-5
+6.8 x 10-5