| 1. | Safety |
| 2. |
Objectives/Overview |
| 3. |
Procedures |
|
4. |
Observations |
| 5. | |
| 6. | |
| 7. | |
| 8. | Conclusions |
| 9. | Calculations/Set-Ups |
| 10. | Grading Scale |
| 11. | Review Prelab Questions |
|
12. |
Review Postlab Questions |
Experiment
13
Determining
the Concentration of a Solution: Beer's Law
POST-LABORATORY QUESTIONS
SHOW SET-UP FOR ALL CALCULATION PROBLEMS
1. A student used 5.0 mL of 0.40 M nickel(II) sulfate solution to make 10.0 mL of working solution. What is the molarity of the new solution?
2. The absorbance of a 0.18 M colored solution was measured with red
light and found to be 0.281. If the same cuvette were cleaned, used,
and dried what would you predict the absorbance to be for each of
the following solution
concentrations?
a. 0.27 M solution
b. 0.36 M solution
c. 0.90 M solution
3. In this experiment, you determined the concentration of an unknown
solution. How would the concentration of the unknown be affected by
the following?
a. The cuvettes were not dried properly leaving some drops of water behind.
b. You consistently used the top of the meniscus for volume readings, rather than the bottom. That is, all pipette measurements used the top of the meniscus.
c. A cuvette was used that had twice the width of the regular cuvette. Assume that the cuvette would fit your colorimeter and that width is the portion of the cuvette turned toward the light source.
