the mixture was (50% benzoic acid, 40% benzoin, 10% dibromobenzene)the report must include (introduction, observation, discussion, conclusion)the mixture i used = 0.503gmethylene chloride = 4 mlsodium hydrous carbonate =4 mlthen i removed the aqueous layer to another test tube6M HCl was to the aqueous layer then saturated sodium chloride weight of the filter paper with benzoic acid (0.172 + 1.868)for the organic layer i added ethanol to recrystallize (benzoin, dibromobenzene)the filter paper for the organic component + crystal (0.180 + 0.23)
Separation and Purification Lab Report Organic Chemistry I Lab
Lab reports should reflect portions of a scientific paper as if you were submitting it to a journal for review. Lab reports should be typed and double spaced. These are a professional document and should be treated as such. You should write appropriately; in a concise, precise, specific manner, omitting non-scientific terminology, slang, undefined abbreviations, etc. Misspellings, consistent errors in grammar, procedural errors, etc., will cause you to lose points. None of the lab report should be written in first person.
It is important that you follow these guidelines when writing your lab reports. Failure to do so will result in loss of points. If in doubt about any rule/suggestion feel free to ask me or your TA
Lab reports are due at the start of the next lab. They should include:
- Title (4 points)
- Provide the title of the experiment or provide an original title.
If you use an original title be sure that it is meaningful and to
- Introduction (28 points)
- Reason for carrying out the experiment (minimum of two
- All structures/mechanisms should be drawn using a chemical drawing program). Structure of reagents are important it should be included if they help explain your introduction.
- The introduction gives the historic importance of an experiment. For example, why would being able to separate and purify compounds in chemistry be important? You should give specific examples from reliable sources, any information that is not common knowledge needs to be cited, this includes your lab manual.
What is the importance of the experiment? I should know what to expect in the report based on this section, but be careful not to include procedural details. You should include background information and/or state the hypothesis you wish to test. You are encouraged to use one or more reference(s) from a scholarly journal. Some of these may also be useful during the discussion. This must be referenced in
the background information. Make sure that all background information is relevant to the experiment being conducted. Avoiding stating, “The purpose of this experiment…” or “This experiment showed that…”. These phrases are not needed and are implied if the section is written appropriately. Important information about techniques or instrumentation can be incorporated into this section.
3. Methods (20 pts)
Context in which results occurred [brief procedure].
o Explain techniques
o Be clear and concise.
o Adapt the procedure from the lab manual but use your
o Written in past tense
In this section you should state the procedure in enough detail that a fellow student could repeat the experiment you conducted without the aid of the lab manual. Sometimes the use of a table or flow chart would be useful to represent procedure. You must be descriptive. It is important that you write what you did rather than what the lab manual states. How much did you use (exactly, use correct significant figures)? What temperature did you heat the reactants to and for how long? Often it is good to include the type (model) of equipment that you used.
4. Results (20 pts)
Section describing outcome of lab
o Include observations of product, mp, etc.
o Use tables, graphs, etc to express information. o Written in present tense
You should use figures, equations, graphs, schemes, or tables to present your data when appropriate. These should be clearly labeled and numbered (Table 1, Table 2, etc.). Each one needs an appropriate label. Depending on the data that you are trying to represent will determine which method you choose. Tables are useful to just show a number. Graphs are good to show trends. The data does not need to be shown for each measurement (that is in your lab notebook). The majority of the time a table will represent your data much more effectively than stating ‘The mass of the vial is…’, ‘The mass of the vial plus product is…’. Just make a table and save us both some time. It is important to still provide a narrative for your results. Do not just rely on graphs, tables, etc.
Important observations and values from calculations should also be shown. You do not need to include each step in the
calculations. Those are in your lab notebook. State any important variables that you observed (mp, bp, Rf).
5. Discussion (28 pts)
- Discussion (a section about the outcome, problems
- Explain your results. You should demonstrate some thought that supports your data. Information from lecture is useful here.
- The lab should be wrapped up in this section and it should be clear what you have learned.
Explain why your results are import in this section. If you know of any sources of error be sure to include them. For example, if you accidently added something you should not have or if you heated the sample longer than you should have. Error is a small part of a discussion and should not be the main feature. It would be excellent to suggest some experiments that could be done next based on your results. Including some material from your cited sources supporting the explanation you gave for your results would be good. This is the most important section and must show understanding.
6. Lab Notebook (10 pts)
- Everything you do should be written down!
- Include your name, date, and title of experiment on every page. Sign and date your data from the lab.
- Raw Data
- Calculations (carried out in the lab notebook, show work). It is fine to only show one representative calculation.
- Carbon copies should be turned in with your lab report.
- If I could not conduct the lab and obtain your results from
reading your notebook then you are not being detailed enough.
This is where you record your data. Any measurement that you take should be recorded here. Use significant figures.
Observations are also included here. Anything that you notice (color, shape, viscosity, etc.) could be recorded, but make sure that it
is relevant to your experiment. You may also find it useful to sketch a diagram of the set-up you used to conduct the experiment. This is particularly useful when you deviate from the lab book.
Calculations should we written out step by step. Each calculation should be easy to follow. Any formulas or constants should be stated.
Tips for better writing:
1. Points will deducted for any of the errors listed below.
o Double space, font size of 12, use either Times New Roman or Arial (be
consistent even in tables, graphs, and molecular drawings. o Print front to back if possible.
o No space between paragraphs.
2. Proofread everything you write. Asking someone in the class to read it for errors would be an excellent idea.
3. Do not
ALL CAPITAL WORDS are not needed, unless it is an accepted acronym.
Use spellchecker. Proofreading is still important since spellchecker will not catch the difference between from and form. Spellcheck will often say that scientific words are spelled incorrectly. Double check.
Check singular/plural forms: hypothesis/hypotheses, spectrum/spectra
To, too, two their, they’re, there are/our allowed/aloud
affect/effect then (related to time)/than (comparison)
plagiarize. You will be turned into the Dean.
Best to read the source and put it away. Then write using your own words and then check for accuracy.
Turning in your previous work in place of a current assignment.is a form of plagiarism.
Turning in the same work as another student is considered plagiarism.
4. Numerals should not start sentences (Nine rather than 9). “Acetone (50.0 mL) was added to the mixture.” Do not say, “50.0 mL of acetone was added to the mixture” or Fifty milliliters of acetone was added to the mixture”.
o Significant in science has real meaning. Do not use it unless you have the math to back it up.
o Don’t spell out numbers to start sentences unless they are exact numbers. They lose their significance.
5. Be concise; use as many words needed to state important information, but avoid repeating yourself.
o Avoid words such as: first, second, then, next, really, and very. They are often not needed and do not change the meaning of the sentence.
o Anything you write is assumed to have occurred after your previous descriptions, thus, you do not need to say ‘then’ after every sentence.
- The actions described should be in the past tense; however, results/facts should be in the present tense since they still exist in the present. The action has occurred so, “The solution was stirred for 30 minutes.” The results are present, “The boiling point of water is 100o C”, not “The boiling point of water was 100o C”.
- Avoid stating, “I heated a solution to 75o C for 15 minutes.” Rather state, “The solution was heated to 75o C for 15 minutes.” Anyone should be able to conduct the experiment so avoid using words that describe yourself (I, we, my, me, us, one, experimenter, student).
- You should not use quotations from your lab book or from a journal article.
o Even when you use your own words, you must cite the source if you took
their idea. If you did not know it prior to writing the report then you must cite the information.
- Do not make up results! It is far more important for you to understand the lab. Resist the urge to fudge your results if they are not like your friends. State what actually happened. Use the discussion section to indicate why you may have been slightly off.
o There is always the chance that your friend is wrong and you are right. o Organic chemistry teaches you that labs do not always work. It will not
always work for you and you should expect that some weeks you will not have results.
- Use italics for other languages (ortho, para, meta). Boldface is not needed.
- Download a chemical drawing program. All reactions should be made using this
program. Do not draw reactions by hand in your report.
- When you plan to use abbreviations, place them after the first time you have spelled out the words completely. Deoxyribonucleic acid (DNA).
o This is not needed for grams (g), milligrams (mg), moles (mol), liters (L), milliliters (mL), hour (h), minute (min), second (sec), etc.
- All graphs, tables, figures, and charts need to be numbered and have a caption. o They should be referenced in the text.
o Should be on the same (or next) page in which they are referenced.
o The caption can be as long as needed to explain to the reader what information is being conveyed.
14. Authors are referred to by their last name. Use a journal article as an example. o Do not say, “In a paper titled “The Novel Synthesis of Hydrogels… by
Nathaniel Beres”. That is in the citation. Just state the information you
want to use followed by (Beres, year).
o Two articles by the same author in the same year cite as 2010a and 2010b.