Lab Report for KHT Solubility Experiment

Your assignment is to write a complete laboratory report. This report should include sections titled: Introduction, Procedure, Results, and Discussion.

INTRODUCTION: (~2 or more pages)
Your introduction should give a short description of the purpose of the experiment. Other items to include in the introduction are:
• important reaction equation(s), clearly explained
• how an equilibrium expression is written for any given reaction
• why solids and liquids are not included in equilibrium expressions
• what a large (or small) equilibrium constant means
• what a “solubility product constant” is and what the “molar solubility” of a solid means
• what effect adding or subtracting reactants (or products) has on the equilibrium (i.e. Le Chatelier’s Principle)
• how titrations work, why phenolphthalein is used, and what the “endpoint” represents
• how KHT’s molar solubility and solubility product constant are determined/calculated
• any other topics that would be necessary to provide appropriate background for this experiment
See information on the back of this handout describing use of references in this section of your lab report.

PROCEDURE: (~1-2 paragraphs)
Describe the general procedure used in the experiment. Do not use the procedure that you wrote out prior to doing this experiment; the tense, sentence structure, and content should be a little different. Be sure to describe how you prepared the 0.0 M (pure water), 0.05 M, and 0.10 M solutions (and say which solutions you used – KCl, MgSO4, or glucose), but do not include small details like what size beakers or flasks that you used.

RESULTS: (Use the report sheet from the lab manual) Also include a table that summarizes your class’s results for solubility in pure water, in KCl(aq), in MgSO4(aq), and in glucose(aq).

DISCUSSION: (~1 or more pages)
You should address the overall purpose of the experiment. Discuss your solubility product constant result. Describe the observed class results for KHT solubility in each of the solutions. Discuss what, if any, effect the presence of KCl, MgSO4, and glucose had on the molar solubility of KHT. Then you must explain why each of these compounds had the observed effect on the solubility of KHT. It is not enough to state that “Compound X caused an increase in the molar solubility of KHT”.

Discuss at least two sources of error that could affect the experiment. Explain what specific effect each would have had on the results of the experiment. (e.g. If you were describing what would happen if you forgot to tare a piece of weighing paper before you weighed a solid on it, you shouldn’t say “it would cause the recorded mass to be wrong”. You need to say “it would cause the recorded mass to be too high”. Then go on to clearly explain how this error would affect the calculated molar solubility of KHT. By the way, please try to describe more sophisticated sources of error than forgetting to tare your weighing paper.)

Plagiarism Reminder:
Plagiarism occurs when a student represents someone else’s work as his or her own; it includes:
• Copying another person’s paper
• Copying another person’s words or ideas without putting quotation marks around them or citing them as a source
• Copying entire sentences and paragraphs from a print or electronic source without providing proper documentation and credit
• Allowing another person to write your paper and make revisions to your work

Any student who plagiarizes, whether from published material (such as a web site, book, or magazine) or from unpublished material (such as another student’s writing), will receive an F on the assignment and, depending on the extent of cheating, an F for the course. Learn more about plagiarism, both in the Student Handbook under “Academic Dishonesty” and also on the Campus Writing Center’s web site.

There should be some type of reference(s) used for information that you include in your introduction section. Your source may be your textbook, your professor, another reference book, or perhaps another source altogether. No matter what the source is, you must include some reference. This is especially true if you give a definition or take something word for word (by the way, it’s much better to paraphrase) from a source. You will be marked down (or receive a failing grade on your lab report) if plagiarism is present in your report. Be safe: remember to reference your sources.

The standard reference format you should use in a general chemistry lab report is the following: Author(s) Title Date of publication, edition (or volume if it is a journal), page numbers. More specific referencing style is described in upper level chemistry courses.

In some cases, it might be necessary to reference your professor. If so, your reference should read Dr. Kevin Pate, personal communication. You should try to find book or journal references if at possible, but you may use this type of personal reference if you have no other choice.