Experiment EQ-320
Post-Lab Questions
Spectrophotometric Determination of An Equilibrium Constant
(To be answered in the "Analysis" section of your lab report)
1. Include a copy of a computer-generated graph for each pair of runs. Place the graphs in order and make sure they are correctly titled for credit. (See question 3 to make sure they are complete)
2. a) Calculate the molarity of the KSCN solution provided.
b) Calculate the molarity of the 0.002M Fe(NO3)3 solution provided.
3. a) Determine [SCN-]ini for solutions 1-5. (You will use your graph for this.)
b) Determine the best straight line through the points in the computer-generated graph of absorbance vs. [FeSCN+]eq for solutions 1-5. This needs to be done very accurately.
4. a) Using the graph in #3 above, determine [FeSCN+]eq for solutions 6-9
b) Calculate [Fe3+]ini for solutions 6-9
c) Calculate [Fe3+]eq for solutions 6-9.
d) Calculate [SCN-]ini for solutions 6-9.
e) Calculate [SCN-]eq for solutions 6-9.
f) Calculate K for each solution, 6-9. Does K seem to be a constant?
g) Calculate the average value of K. Is the reaction favored? Why or why not?
Post-Lab Questions
Experiment EQ-320
Spectrophotometric Determination Of An Equilibrium Constant (To be answered in the "Analysis" section of your lab report)
2. a) Calculate the molarity of the KSCN solution provided.
b) Calculate the molarity of the 0.002 M Fe(NO3) solution provided.
3. a) Determine [SCN-]ini for solutions 1-5. (You will use your graph for this.)
[FeSCN2+]eq for solutions 1-5. This needs to be done very accurately.
4. a) Using the graph in #3 above, determine [FeSCN2+]eq for solutions 6-9
b) Calculate [Fe3+]ini for solutions 6-9
c) Calculate [Fe3+]eq for solutions 6-9.
d) Calculate [SCN-]ini for solutions 6-9
e) Calculate [SCN-]eq for solutions 6-9.
f) Calculate K for each solution, 6-9. Does K seem to be a constant?
g) Calculate the average value of K. Is the reaction favored? Why or why not?
