CHEM 1412: Instructor Course Requirement for Original Procedure You will be choosing
CHEM 1412: Instructor Course Requirement for Original Procedure
You will be choosing one lab experiment from a list of choices to write a lab procedure for a hypothetical CHEM 1412 student to follow in the future. The purpose of this exercise is to demonstrate your understanding of your own lab skills you have developed this semester and to analyze what steps must be taken to solve a research problem. This practice of experimental design is carried out daily by researchers. Taking existing knowledge of various concepts and piecing them together in new ways is a highly sought-after critical thinking skill that employers and universities desire in virtually any field. Note: you are only writing the procedure; this experiment will not actually be performed in our lab.
General instructions:
See lab ICR calendar for due date.
Late reports may be graded with a penalty of 10 points per 24-hour period late. Late reports may be submitted only during office hours or by email. No late reports will be accepted after the lab final exam.
The entire procedure must be typed with 12-pt reader-friendly font of your choice, 1.5 line spacing, 1-inch margins.
The procedure must follow all safety regulations, and you should write into your procedure any specific safety considerations (ie if a portion of the experiment should be performed in the fume hood). Consult and cite the MSDS for chemicals in your experiment for assistance with this.
The procedure must be neat, grammatically correct, and free of spelling errors.
You may use only second or third (not first) person.
The procedure must be the student’s own work. If you are using your lab manual or an outside source(s) for assistance in developing your procedure, you must cite your source(s) at the end of the procedure, and the steps in your procedure need to be in your own words. If multiple students’ procedures have identical/extremely similar wording or if your wording is too similar to any source, points will be deducted from each such procedure.
All procedures should be written so as to fit in one three-hour lab period (unless drying for one or more days is necessary, in which case only drying instructions can be written for the following lab period).
All procedures should use only equipment available in our general chemistry lab. If you are unsure whether a piece of equipment or chemical is available in our lab, be sure to ask your instructor.
The steps of your procedure should tell the student how to fully complete the research problem and should take into consideration convenience to the hypothetical student performing the experiment.
Experiment Choices: Select only one of the following for which you would most like to write a procedure. You should not answer the research problem yourself (for example, you do not have to actually determine the dissociation constant of an unknown base in choice #1). You only need to design a procedure that will allow the hypothetical student performing the experiment to answer the research problem.
Research problem: Determine the dissociation constant and molarity of an unknown weak base.
This procedure should involve a strong acid-weak base titration with multiple trials.
The strong acid needs to be standardized as part of the procedure.
A pH meter will need to be used for a portion of this experiment.
Research problem: Select the best oxidizing agent and reducing agent from the following list of metal ions: Zn2+, Mn2+, Ag+, Cd2+, Co2+, Cr3+, Ni2+
This procedure should involve constructing voltaic cells.
The procedure should be written in such a way that all reactions will occur spontaneously.
You should provide the student one (and no more) of the standard reduction potentials of the seven ions.
You may not have the student use the same metal in every voltaic cell. At least one voltaic cell should utilize other metals. (For example, if you give instructions for the construction of 12 voltaic cells, you may only use Zn2+ in a maximum of 11 of the cells.)
Have the student include in their report the shorthand cell notations for each voltaic cell.
Note: If you choose this option, you will need to include an extra section at the end of the document (after the Works Cited section) entitled “Behind the Scenes.” In this section, you will show whatever work you had to do or thought process you used to determine the combinations of metals you used in each voltaic cell. You may organize this section however you wish, but you must offer some sort of explanation of how you chose to assign each metal as the anode and cathode. This section must also be typed. This section will be worth 10 points out of the 70 procedure points.
Research problem: Colorimetrically determine the percent of copper in an unknown solid ionic compound.
This procedure should involve the use of a spectrophotometer in two parts of the experiment: 1) constructing a calibration curve, and 2) using the calibration curve to analyze an unknown.
The reaction used to make the copper detectable by the spectrophotometer in both parts of the experiment should be the addition of NH3 to Cu(NO3)2 to form the deep blue-colored complex [Cu(NH3)4]2+.
The hypothetical student should be instructed in the first part of the experiment how to construct a calibration curve from known [Cu(NH3)4]2+ concentrations.
The student should be instructed to use the calibration curve in the second part of the experiment to find the percent of Cu in the unknown solid ionic compound. There should be multiple trials for this part so that an average percent of Cu can be found, along with standard deviation.
Note: when performing this reaction, solid Cu(OH)2 precipitates initially when mixing the reactants. Adding an excess of NH3 and swirling dissolves the solid.
Note: If you choose this option, you will need to include an extra section at the end of the document (after the Works Cited section) entitled “Behind the Scenes.” In this section, you will show two stoichiometry calculations for how much NH3 you decided to use in both parts A and B. Tip: NH3 should be the excess reagent and the Cu substance should be the limiting reagent in the both parts, and you will need to show what the unknown is for part B in order to do the stoichiometry calculations. This section will be worth 10 points out of the 70 procedure points.
Procedure Sections and Percent of Procedure Grade:
The sections of your procedure must be labeled and appear in the order given below.
Heading ………………………………………………………………………………………..………………….……..5%
Include a heading with your name, course, lab day and time, instructor, date the procedure is being submitted, and title of the experiment you are choosing. Choose an appropriate title that accurately describes your experiment.
Objectives.………………………………………………………………………………………………………….…. 10%
Include a brief paragraph summarizing the key goals/purposes of this specific experiment and the general methods that will be employed to achieve those goals. This section should be 3-5 complete sentences long. This section should be written in such a way that the hypothetical chemistry student could read the objectives and will have a good idea of what all will be accomplished in this experiment and how it will be accomplished. Explain, rather than simply list, the methods that will be used, meaning the reader should have a good idea of how those methods will help accomplish the goals. This section must be in your own words, not copied directly from the lab manual or another source. Use complete sentences.
Materials …………………………………………………………………………………………………………….…. 15%
Include a list of all equipment and chemicals the hypothetical student performing the experiment will need. Consider each step of the procedure and what equipment and chemicals will be required and whether the student will need to arrange some of the equipment into a more complex setup. For example, if you are having the student heat with a Bunsen burner, he or she will need a ring stand, ring clamp, wire gauze, etc. If you mention water, specify whether tap water or DI should be used. If you use a solution, include its molarity.
Procedure……………………………………………………………………………………………………………………65%
The procedure should be written in enough detail so that the hypothetical student can perform the experiment using your procedure, while accomplishing the research goal as efficiently and accurately as possible. Do not skip steps and assume the student will know to perform them. The format of the steps of your procedure must be a numbered list. Each step should be short (one or two complete sentences). When deciding on quantities of chemicals for the student to measure, you may wish to use the most similar experiment in our lab manual as a guide. Be sure to tell the reader when they need to stop and record observations and/or data. You do not, however, need to design a blank report sheet where the hypothetical student would record data. Assume the hypothetical student will make his or her own report sheet from the data you tell him or her to record. You are only writing the steps for him or her to follow. Use complete sentences in this section.
Works Cited…………………………………………………………………………………………………………………5%
You may use any recognized format (such as APA) for citing your source(s), including your lab manual, an individual Material Safety Data Sheet for each chemical used, and any other sources you used.
**Only include the following “Behind the Scenes” section if you choose option #2, “Select the Best Oxidizing Agent and Reducing Agent…”. If you choose option #1 or #3, you do not need to include the following section.**
Behind the Scenes………………………………………………………10% out of the 65 procedure points
See the explanation above in the bullet points for option #2.[supanova_question]