2. Fe3+ (aq)
SCN- (aq)
Fe(SCN)2+ (aq)
colorless
colorless

3. Fe3+ (aq) Fe(SCN)2+ (aq) + SCN- (aq) colorless colorless
reddish-orange

4. equilibrium [Fe(SCN)2+], M
Standard Solutions for calibration curve
Pg. 32
A (blank) B C D E
volume of M Fe3+
10.0 mL
volume of M SCN-
0.00 mL
0.50 mL
1.00 mL
1.50 mL
2.00 mL
0.200 M HNO3
dilute to mL mark
equilibrium [Fe(SCN)2+], M
0.00
4.00 x 10-5
8.00 x 10-5
12.0 x 10-5
16.0 x 10-5

5. Standard solutions Standards [Fe(SCN)2+], M absorbance standard A 0.00
standard B
4.00 x 10-5
standard C
8.00 x 10-5
standard D
12.0 x 10-5
standard E
16.0 x 10-5
Pg. 36

6. Standard solutions Standards [Fe(SCN)2+], M absorbance standard A 0.00
0.000
standard B
4.00 x 10-5
0.196
standard C
8.00 x 10-5
0.371
standard D
12.0 x 10-5
0.557
standard E
16.0 x 10-5
0.759
Pg. 36

7. Experimental test solutions
absorbance
[Fe(SCN)2+], M
solution 1
solution 2
solution 3
solution 4
solution 5
Pg. 36

8. Experimental Solutions Pg. 34
Blank 1 2 3 4 5
mL M SCN-
0.00
0.50
1.00
1.50
2.00
2.50
mL M Fe3+
mL M HNO3

9. Experimental test solutions
absorbance
[Fe(SCN)2+], M
solution 1
0.139
solution 2
0.278
solution 3
0.414
solution 4
0.546
solution 5
0.658
Pg. 36

10. Standard solutions Standards [Fe(SCN)2+], M absorbance standard A 0.00
0.000
standard B
4.00 x 10-5
0.196
standard C
8.00 x 10-5
0.371
standard D
12.0 x 10-5
0.557
standard E
16.0 x 10-5
0.759
Pg. 36

12. Experimental test solutions
absorbance
[Fe(SCN)2+], M
solution 1
0.139
2.96 x 10-5
solution 2
0.278
from graph
solution 3
0.414
solution 4
0.546
solution 5
0.658
Pg. 36

14. Experimental test solutions
absorbance
[Fe(SCN)2+], M
solution 1
0.139
2.96 x 10-5
solution 2
0.278
5.92 x 10-5
solution 3
0.414
from graph
solution 4
0.546
solution 5
0.658
Pg. 36

15. [Fe(SCN)2+]equil (graph)
Experimental test solutions
units are M 1 2 3 4 5
[Fe(SCN)2+]equil (graph)
2.96 x 10-5
[Fe3+]initial
[SCN-]initial
[Fe3+]equil
[SCN-]equil K
Average K

16. Initial Concentrations for Trial 1

17. [Fe(SCN)2+]equil (graph)
Experimental test solutions
units are M 1 2 3 4 5
[Fe(SCN)2+]equil (graph)
2.96 x 10-5
[Fe3+]initial
1.00 x 10-3
[SCN-]initial
[Fe3+]equil
[SCN-]equil K
Average K

18. [Fe(SCN)2+]equil (graph)
Experimental test solutions
units are M 1 2 3 4 5
[Fe(SCN)2+]equil (graph)
2.96 x 10-5
[Fe3+]initial
1.00 x 10-3
[SCN-]initial
[Fe3+]equil
[SCN-]equil K
Average K

19. Initial Concentrations for Trial 1

20. [Fe(SCN)2+]equil (graph)
Experimental test solutions
units are M 1 2 3 4 5
[Fe(SCN)2+]equil (graph)
2.96 x 10-5
[Fe3+]initial
1.00 x 10-3
[SCN-]initial
2.00 x 10-4
[Fe3+]equil
[SCN-]equil K
Average K

21. x = [Fe(SCN)2+]equil (obtained from graph)
Fe3+ (aq)
SCN- (aq)
Fe(SCN)2+ (aq)
initial
1.00 x 10-3
2.00 x 10-4
change x +x
equilibrium
1.00 x 10-3 x
2.00 x 10-4 x x
x = [Fe(SCN)2+]equil (obtained from graph)

22. Equilibrium Concentrations for Trial 1
[Fe3+]equil = [Fe3+]­initial – [Fe(SCN)2+]equil
[Fe3+]equil = x 10-3 M – x 10-5 M
= x 10-4 M
[SCN-]equil = [SCN-]­initial – [Fe(SCN)2+]equil
[SCN-]equil = x 10-4 M – x 10-5 M
= x 10-4 M

23. [Fe(SCN)2+]equil (graph)
Experimental test solutions
units are M 1 2 3 4 5
[Fe(SCN)2+]equil (graph)
2.96 x 10-5
[Fe3+]initial
1.00 x 10-3
[SCN-]initial
2.00 x 10-4
[Fe3+]equil
9.70 x 10-4
[SCN-]equil K
Average K

24. [Fe(SCN)2+]equil (graph)
Experimental test solutions
units are M 1 2 3 4 5
[Fe(SCN)2+]equil (graph)
2.96 x 10-5
[Fe3+]initial
1.00 x 10-3
[SCN-]initial
2.00 x 10-4
[Fe3+]equil
9.70 x 10-4
[SCN-]equil
1.70 x 10-4 K
Average K

25. Determine the numerical value of the equilibrium constant, K
= 179

26. [Fe(SCN)2+]equil (graph)
Experimental test solutions
units are M 1 2 3 4 5
[Fe(SCN)2+]equil (graph)
2.96 x 10-5
[Fe3+]initial
1.00 x 10-3
[SCN-]initial
2.00 x 10-4
[Fe3+]equil
9.70 x 10-4
[SCN-]equil
1.70 x 10-4 K
179
Average K