STEM Chemistry at GBS
The Laboratory

Home || Schedules || Laboratory || File Cabinet || Quiz Room || Helpful Resources

Unit 8: Kinetics and Equilibrium Notebook Labs

View Scoring Rubrics (link coming soon)


The following items should be in the Unit 7 portion of your notebook.  They should be clearly organized and easy to find.  Use an organizational system and label all work. Each lab will be graded separately.  All lab grades will be entered into the gradebook. 





Lab KE1 - Reaction Rates

Question:
What is the effect of reactant concentration, temperature, and surface area upon a reaction rate? How can the effects be explained using collision theory?

Purpose:
To plan and design a set of experiments to determine the effect of reactant concentation, temperature, and surface area upon the rate of reaction and to explain the effect using the principles of collision theory.


Safety:
As always, weare goggles to protect vision from splashing solutions. Given the nature of the lab, it is more important than ever to always be protected.

Disposal:
All table messes should be cleaned using a wet sponge or paper towel before leaving lab. Solutions can be disposed down the drain. Solids should be dumped in the garbage can.

A complete lab write-up includes a Title, a Purpose section, a Data section, a Conclusion section, and a Discussion of Results section.  The Data section includes an organized documentation for each "mini-experiment"; this should include a graphical and/or annotated description of the procedure performed during the mini-experiment. The Conclusion should briefly and conclusively describe the effect of reactant concentration, temperature, and surface area upon reaction rate.  The Discussion of Results section should thoroughly and logically explain these effects using the principles of collision theory.  





Lab KE2 - Feeling Blue ... No Longer

Question:
What is the effect of temperature and reactant concentration upon the rate of reaction and how can these effects be explained?

Purpose:
To determine the effect of temperature and reactant concentration upon the rate of reaction and to use principles of collision theory to explain such effects.


Safety:
Potassium hydroxide solution is a corrosive; avoid contact with eyes and skin. Methylene blue is slightly toxic by ingestion. Wear chemical splash goggles at all times. The dextrose sugar solution will attract ants so clean up any spills with plenty of water.

Disposal:
Once neutralized, solutions can be poured down the drain and rinsed thoroughly with water.

A complete lab write-up includes a Title, a Purpose section, a Data section, a Conclusion section, and a Discussion of Results section.  The Data section includes an organized table of data for both parts of the lab;  the data table should include labeled column headings and units. A calculation of reaction rate should be shown for one of the trials in each part of the lab. The Conclusion should briefly and conclusively describe the effect of temperature and concentration upon reaction rate.  The Discussion of Results section should thoroughly and logically explain both of these effects using the principles of collision theory.  






Lab KE3 - Red-Grey Equilibrium Simulation

Question:
How does a reversible system respond over time and what observations can be made of the amounts of reactants and products for such a reversible system?

Purpose:
The purpose of this activity is to simulate the concept of equilibrium and the tendency of a system to always achieve an equilibrium position.

This lab will NOT be written up in your lab notebook.  You will be provided with a handout and hand the handout in when the lab activity is complete.







Lab KE4 - LeChatelier's Principle

Question:
How and why does a stress or disturbance alter the position of the equilibrium for a reversible reaction?

Purpose:
To study the equilibirum system involving 

Co(H2O)62-(aq)  +  4 Cl-(aq)  <====> CoCl42-(aq) + 6 H2O(l)

and to use the color of the Co(H2O)62- (pink) and the CoCl42- (blue) to determine the effect of various stresses upon the equilibrium position and to explain why each stress caused the observed shift in the equilibrium position.


Safety:
Hydrochloric acid is highly toxic by ingestion or inhalation and is severely corrosive to skin, eyes and clothing.  Ethyl alcohol and acetone are flammable solvents.  Cobalt (II) chloride solution is moderately toxic by ingestion.  Silver nitrate solution is corrosive and will stain your skin and clothing upon contact.  Wear safety goggles at all times.

Disposal:
Give your silver nitrate test tube to your instructor.  All other solutions can be poured down the drain and rinsed thoroughly with water.

A complete lab write-up includes a Title, a Purpose section, a Data section, a Conclusion/Discussion of Results section.  The Data section includes an organized table of data describing both the procedural test and the observed outcome for each test tube;  observations should be clearly recorded. The Conclusion/Discussion should identify the seven stresses studied in this experiment, identify the direction which the equilibrium shifted as a result of the sress, and logically explain each of the equilibrium shifts using LeChatelier's Principle.

The following information may be useful in interpretting your results:

  • Hydrochloric acid solution (test tube C) contains dissociated HCl.
  • Calcium chloride (test tube D) to its ions when dissolved in water.
  • Acetone (test tube E) reacts with liquid water and removes it from the eqilibrium system..
  • Silver nitrate (test tube F) solutions contain silver ions;  silver reacts with Cl- ions to form a precipitate.






Lab KE5 - Solubility Product Constant

Question:
What is the solubility product constant for silver sulfate?

Purpose:
To determine the solubility product constant (Ksp) for silver sulfate.

Safety:
Assume all solutions are toxic by ingestion.  Wash your hands with soap before leaving the lab.  Wear safety goggles at all times.

Disposal:
All solutions should be placed in the separate waste bin found in the fume hood.

A complete lab write-up includes a Title, a Purpose section, a Data section, a Conclusion, and  a Discussion of Results section.  The Data section should include a table with an organized and labeled listing of known and measured quantities (with units) for the three separate trials.  A calculation section should follow in which measured quantities are used to calculate the Ksp.  A balanced chemical equation and clearly shown concentrations calculations must be included;  each step should be clearly annotated with a brief statement of what is being calculated. Calculations should be shown for only one trial. (Assume solution densities of 1.0 g/mL.) The Conclusion should respond to the question raised in the Purpose of the lab. The Discussion of Results section should identify the theoretical value of the Ksp of silver sulfate (1.4 x 10-5) and include an error analysis;  As always, the error analysis should respond the question How well did you do?;  a percent error calculation should be included; work should be shown.  Possible sources of error should be described.









Home || Schedules || Laboratory || File Cabinet || Quiz Room || Helpful Resources