Chem 333L is a one-credit laboratory course covering analytical techniques important to environmental testing. Volumetric, electrochemical, chromatographic and spectroscopic techniques are covered. Students learn how to prepare samples and how to make accurate and precise measurements. Particular attention is given to data analysis and evaluation of data.
Tu 6:10 - 9:00 PM
MWF 10:10-11:00, MW 3:10-4:00, T 1:10-2:00, F 12:10 – 1:00 or by appointment
web page: http://WEBPAGES.SHEPHERD.EDU/DDILELLA/
CHEM 333 should be taken concurrently.
Students are expected to attend all laboratory sessions. Students must get their lab notebooks signed during each period. Makeup labs will not be administered without a valid written excuse. Labs that are missed with a valid excuse may be made up at a time determined by the instructor. Students may NEVER work in a lab without permission of the instructor.
Cheating in all its forms, including plagiarism and cheating on visual work, is considered an academic matter and will result in automatic dismissal from the course and will be recorded on the official transcript.
The primary purpose of a lab notebook is to have a complete record of what you did in lab. In principle, you should be able to use the combination of the written lab procedure and the lab notebook to figure out exactly what happened in an experiment. The notebook entries need to be complete enough so that another person should be able to reproduce your work using this information. If you were to lose a lab report you should be able to completely reproduce it based on the information in the notebook. The notebook is placed where you first write all data and record all observations.
The lab notebook should be a bound notebook, not a loose-leaf binder or a ring binder. When you start a new notebook, use a pen to number each page from the first page through about fifty pages. Put the number in the upper, outside corner of each page. Never remove pages from this notebook. All entries should be in pen. All entries should start on the first page and then continue on consecutive pages.
On the first page, put your name and course number . You may want to put you address and/or phone number here in case your book is lost.
In your notebook, each lab exercise should start on a new page. The first page for each experiment in the notebook should have the following at the top of the page:
Title of experiment, date, partners names (if applicable). Each addition page used should have the date and the title.
Always write in pen. If you have mistakes put a single line through the part in error. You should still be able to read the original entry since people sometimes cross out things that they later realize were correct. All data collected in the experiment should be written first in the notebook. Don’t worry about having a perfectly neat and clean notebook. A real lab notebook never looks impeccably neat and clean because, if it is used correctly, it will probably be stained and have a fair amount of crossed-out data.
All data should have appropriate units and an appropriate number of significant figures. For example, the weight of a penny on an analytical balance should be reported as 2.5345 g. If the weight had been 2.5000 g it should be entered with four decimal places. 2.5 g does not mean the same thing. It is usually best to organized data into a table if possible. In that case the units can be placed at the top of the column.
You do not have to write the complete procedure for every part of the experiment. You can assume that the details are in the lab manual. However, any changes in procedure from those in the manual should be indicated. All data and observations should be written directly into the notebook. This information should be easily correlated with the lab procedure as written in the manual. It is often easiest to organize data if you prepare a table in the notebook before starting the experimental work.
Although not required, it is good practice to include some sample calculations in the notebook.
Graphs and Charts etc.
The graphs or charts that you include in your reports can be duplicated and included in the notebook if you want.
Reports are due one week after the completion of the experimental work. 2 points will be deducted from the score for every day that the report is late. The use of computer spreadsheets for data tabulation, analysis and creation of graphs is strongly encouraged. A properly annotated printout of a spreadsheet is sufficient for the lab report.
Reports should include the following:
The first page should include your name, the title and number of the experiment and the dates on which the experiment was performed and submitted.
ALL data collected must be recorded in your notebook and must be included in the report.
All data should appear in Tables.
All tables should include a title.
All columns in tables should include headings.
All tables entries should have units unless the quantity is unit-less
Estimated uncertainties should be give for all measured quantities.
All plots should have titles.
The axes on plots should be labeled and the dimensions (units) of all quantities should be indicated.
All plots should be computer generated. Plots should be constructed so that they can be read to the maximum possible precision. Adjust the x and y ranges so that they are slightly larger than those needed to contain all of the data points.
A sample calculation showing every step used to treat the raw data should be presented. It is neither necessary nor desirable to show repeated examples of the same basic calculation. Describe the purpose of each step and indicate clearly the source of every quantity which you use in the calculation. Appropriate units should be used throughout the calculation. The sample calculations can be included on the spreadsheet printout. Be sure that purpose of each is clearly indicated.
Deductions will be taken as follows
missing or improper units - 5 pts
missing data - 5 pts
missing sample calculations - 5 pts
The final grades are based on the lab reports and on the notebook. There are no tests or quizzes. Reports are graded on a scale from 0 to 100 and all have equal weight. The score on a report depends on the accuracy of your determination of the unknown and the clarity and completeness of the report. Typically the unknown is worth 20% of the grade but in a few cases, it is worth more. The instructor will give details as the experiments are done.
Grading for Course
The final grade will be based on the following scale
A 90 % to 100 %
B 80 % to 89+ %
C 70 % to 79+ %
D 60 % to 69+ %
The experiments have been designed with safety as a major consideration. However, the equipment and procedures will be unfamiliar to you and mistakes can and will happen. Be sure that you understand the hazards associated with the equipment and reagents before starting an experiment. Do not be afraid to ask questions. SAFETY GOGGLES OR GLASSES MUST BE WORN AT ALL TIMES. STUDENTS MAY NEVER WORK ALONE IN A LAB.
Laboratory experiments will focus on environmentally important samples such as soils, ground water, and plant matter.
Some of the techniques used will include
Atomic Absorption Spectroscopy
High Performance Liquid Chromatography
Gas Chromatography – Mass Spectroscopy
UV Visible Spectroscopy