Teaching Guided-Inquiry Organic Chemistry Labs University of California, Irvine 2007. How does UCI run O-Chem labs. J. K. Kim. ENROLLMENT STATISTICS. 51LA WINTER 2007 SCHEDULE OF EXPERIMENTS. EXP #1 - Monday, January 8 - Friday, January 12, 2007
University of California, Irvine
J. K. Kim
NOTE: Students in Monday sections are scheduled to do the lab work on Wednesday, February 21 instead of Monday, February 19.
NOTE: Carry out the distillation in the hood.
Review Techniques: pp. 100-105 (9.1-9.4), 111 (9.7a), 114 (9.8)-116 (9.9)
- Familiarize yourself with the Appendix in Techniques, page A1 -A6.
- Read the Safetylink. Read the Lab Policies link.
- Read the Keep our lab Clean link.
Supplementary information in Paula Y. Bruice (4th ed): Chapters 1 & 2.
(a) ethanol-methanol (b) hexane-cyclohexane (c) acetone-ethanol
(d) water-ethanol (e) water-cyclohexane
EXPERIMENTAL purifying solid organic compounds. A pure organic compound is one in which there are no detectable impurities. By finishing Experiment #1, you will master the technique starting with two compounds that are structurally different.
1. Attendance at meetings
2. Meeting preparedness
3. Willingness to participate
4. Positive attitude toward group members
5. Overall contribution
Lab reports for Chem 51LA should be written in you lab notebook in ink and consist of the following sections:
TO BE COMPLETED BEFORE YOUR LAB SECTION purifying solid organic compounds. A pure organic compound is one in which there are no detectable impurities. By finishing Experiment #1, you will master the technique starting with two compounds that are structurally different.
2. Date and Lab Partners: The actual date that an experiment was performed as well as the names of other students with whom you were working should be recorded. If you don’t know who you are working with in advance, you should add your lab partners’ names at the beginning of the experiment.
3. Purpose: Every experiment has a purpose! This section should be a brief (but more than one sentence) description of the reason that the experiment is being performed and what methods or techniques will be used. “Because it’s on the lab schedule” is NOT an appropriate purpose for an experiment. Instead, think about what the goals of the experiment are. Will you be separating the components of a mixture of compounds? By what method will you achieve separation? Are you discovering the identity of an unknown compound? What techniques can be used to identify the compound? If there are multiple parts to an experiment, they should all be included here. The clarity of this section will indicate to your TA how well you understand what you will be doing and why you will be doing it.
4. Reactions: If the experiment includes synthesis, the pertinent balanced chemical equation (using structures) should be written here. This section may be omitted when synthesis is not part of the experiment.
5. Table of Chemicals (Including Physical Data): purifying solid organic compounds. A pure organic compound is one in which there are no detectable impurities. By finishing Experiment #1, you will master the technique starting with two compounds that are structurally different. A table of all chemicals used in the experiment along with their physical properties (molecular mass, melting point, boiling point, and density) should appear here. This table should also include the moles (or millimoles) and quantities (mass or volume) of each chemical to be used in the experiment. These calculations must be performed as part of your pre-lab preparation.
6. Procedure: Outline the procedure for the experiment here, including any changes indicate in the handout for the experiment. This section should be written IN YOUR OWN WORDS and in a format that you can easily follow when necessary in the laboratory. You should NOT copy the procedure word for word from the text book or experiment handout! Diagrams or drawings of equipment should be included in this section as well.
TO BE COMPLETED DURING YOUR LAB SECTION
7. Data and Observations: In this section you should record any data collected during the experiment as well as the ACTUAL amounts of chemicals used. Note any observations you make during the course of an experiment such as a color change, the presence or disappearance of a solid, and any difficulties experienced. Be detailed when recording observations. When an experiment fails, you may need to rely on these observations to determine what happened.
8. Results: Briefly summarize the results of your experiment here. Include calculations of percent yield or percent recovery.
TO BE COMPLETED AFTER YOUR LAB SECTION purifying solid organic compounds. A pure organic compound is one in which there are no detectable impurities. By finishing Experiment #1, you will master the technique starting with two compounds that are structurally different.
9. Discussion: This is your chance to write like a scientist. Your discussion should begin with an overview and a brief description of the goals of the experiment. Explain what happened and why, relating your discussion of results to the goals of the experiment. Use your data to support any conclusions drawn. Consider the following questions, if appropriate, when writing your discussion.
a. Do your results make sense?
b. Were the goals of the experiment accomplished?
c. How do your results compare to literature values (melting point, boiling point, spectroscopic data, etc.)?
d. How do your results relate to the underlying theories of the experiment?
e. What are the possible sources of experimental error? How do they relate to your results and the underlying theories of the experiment?
f. What difficulties, if any, were encountered during the course of the experiment, and how did they affect your results? Do these difficulties suggest a better way to conduct the experiment?
g. Do your results raise questions that could be answered by further experiments? What would those experiments be?
h. If you have synthesized a compound, how do you know its identity?
i. If you have isolated a compound, how do you know how pure it is? What is your percent recovery or percent yield?
j. If your percent recovery or percent yield is low, why may that be? Did you lose material along the way? Are you sure you actually made what you think you made, or did you recover reactants? Discussions should be written in the third person passive voice. For example, “We dissolved the white solid in 10 mL of hot water,” should be written as, “The white solid was dissolved in 10 mL of hot water.”
**Oral Discussions: When you are required to present an oral presentation for an experiment, the same questions should be considered as in the written discussion. You are not, however, required to use the third person passive voice. While the group oral discussions should relay the same information as the written discussion, they should not be recitations of written discussions. The oral presentation should keep the attention of and engage your audience. Being able to relay scientific information effectively is a very important skill for any job that you should begin practicing now.
Turning In Lab Reports Your TA will check your notebook during your lab section for all portions of the report except for the discussion. The only portion of the report that needs to be handed in is the discussion during the next lab period or other specified time.