How To Structure A Chem Lab Report

http://www.dartmouth.edu/~chemlab/info/notebooks/sample.html

Density of an Unknown Liquid Objective To determine the identity of an unknown liquid by measuring its density. Reference "Dartmouth College, Chemistry 3/5 Lab Manual", pp. 25 - 37. Prelab Procedure Outline 1. Obtain sample of unknown liquid. Note physical properties such as odor, viscosity, and color. 2. Record the mass of clean, dry 10.00 mL volumetric flask and stopper. 3. Carefully transfer unknown liquid to volumetric flask. Fill to mark exactly. Stopper flask. 4. Measure mass of filled flask. 5. Empty and dry flask. 6. Repeat steps 2 - 5 for additional liquid sample. or Prelab Procedure Flowchart Obtain unknown sample in beaker note odor, color, viscosity Weigh clean, dry 10 mL volumetric flask and stopper record Transfer liquid to flask fill to mark, use dropper, stopper flask Weigh filled flask record Empty, dry flask. Repeat for additional liquids. Sample Calculations: If flask is 10.0 g and flask + liquid is 15.0 g Mass liquid = 15.0 g - 10.0 g = 5.0 g Density liquid = 5.0 g / 10.00 mL = 0.50 g/mL Prelab Analysis Outline 1. Subtract mass of empty flask from mass of filled flask to calculate mass of liquid. mLiquid = mflask & liquid - mflask 2. Divide liquid mass by liquid volume to calculate density. D=mliquid/10.00 mL 3. Compare to known densities to indentify liquid. or Flowchart Calculate Mass Liquid mLiquid = mflask & liquid - mflask Calculate Density D=mLiquid/10.00 mL Compare to known density values Procedure, Data and Results Empty Volumetric Flask Washed two 10.0 mL volumetric flasks and dried with KimWipes, inside and out. Labeled A and B with pencil. Weighed flasks A and B on analytical balance Flask A 11.2571 g Flask B 11.3921 g Filled flasks to mark with unknown liquid 1. Weighed on analytical balance. Emptied and dried flasks A and B. Weighed empty flasks. Filled to mark with unknown liquid 2. Weighed on analytical balance. Unknown liquid 1 Flask A Flask B mass empty flask 11.2571 g 11.3921 g mass flask & liquid 19.2571 g 19.6124 g mass liquid 8.0000 g 8.2203 g Density liquid 0.8000 g/mL 0.8220 g/mL Average density liquid: 0.8110 g/mL Probable Identity: methanol Unknown liquid 2 Flask A Flask B mass empty flask 11.2575 g 11.3918 g mass flask & liquid 21.3308 g 21.5086 g mass liquid 10.0733 g 10.1168 g Density liquid 1.0073 g/mL 1.0117 g/mL Average density liquid 2: 1.010 g/mL Probable Identity: water The first liquid unknown was determined to be methanol from its experimental density of 0.8110 g/mL. This compares to the literature value of 0.7914 g/mL (CRC Handbook, 66th ed., p. C-351). Methanol is colorless, slightly less viscous than water, and has a slightly sweet odor. The second liquid was determined to be water from its experimental density of 1.010 g/mL. The literature value for the density of water at 25 °C is 0.997 g/mL (CRC Handbook, 66th ed., p. F-10). The water sample looked and smelled like water. This method of determining densities was accurate to within 2% for methanol and to within 1% for water. Limitations on the precision of the determination were the ability of the experimenter to correctly fill the volumetric flask, the accuracy of the flask itself, and the accuracy of the balance. The balance is accurate to 0.0001 g out of 19 g (0.0005%) and the flask is accurate to 0.02 mL out of 10 mL (0.2%). Since both of these values are less than the discrepancy between the experimental and literature density values in this experiment, they were not the limiting factors in the precision of the results. Possible error by the experimenter that would account for the experimental precision being less than expected are not filling the flask to the mark properly or having droplets of liquid in the neck of the flask or on the outside of the flask. Handling the flask with bare hands could have introduced an error in the mass by adding fingerprints. Finally, the densities of liquids vary slightly with temperature and this could account for the discrepancy between the experimental results and literature values. If the temperature in the lab was not 25 °C, the true values of the densities of the liquids may have differed from the literature values for 25 °C.

How To Study Chemistry

The inventory below lists behaviors that you should exhibit in order to excel in chemistry. Write true or false beside each of the following statements describing the way you study. The scoring scale at the end

1. I always read the lecture material before I go to lecture.

2. I go over my lecture notes as soon as possible after lecture to rework them and mark problem areas.

3. I try to work the homework problems without looking at the example problems or my notes from class.

4. I go to office hours or tutoring regularly to discuss problems on the homework.

5. I rework all of the homework problems before the test or quiz.

6. I spend some time studying chemistry at least five days per week (outside of class time).

7. I make mnemonics for myself to help me remember facts and equations.

8. I make diagrams or draw mental pictures of the concepts discussed in class.

9. I participate in a study group where we do homework and quiz ourselves on the material

10. I rework all of the quiz and test items I have missed before the next class session.

11. I realize that I can still do well in this class even if I have done poorly on the quizzes and tests up to this point.

The predicted grade for your performance in chemistry is provided below:
Number of True Responses	Predicted Grade
9 or more 6 – 8 4 – 5 2 – 3 less than 2	A B C D F

Note that you can change your predicted grade at any point by changing your behavior such that more of the statements are true.

http://appl003.lsu.edu/slas/cas.nsf/$Content/Chemistry+Study+Strategies+Inventory?OpenDocument

How To Study Chemestry

1. Recopy your notes.
2. Recopy your notes after each lecture. This will reinforce the information you just learned. Make sure you understand what you are recopying.
3. Write your One-Page Summary.
4. This is the key step! Summarize your notes onto one page after the completion of each chapter. (Click here for an example of a One-Page Summary.) It is much easier and more productive to study from the one page of condensed notes.
5. Understand and memorize your One-Page Summary.
6. Don't blindly memorize. You must understand your summary before you memorize it.
7. Do problems.
8. To thoroughly understand the concepts presented in each chapter, do as many problems as you can from your textbook. For extra practice, click the Practice Problems tab and select the appropriate topic. Try to relate each problem to a point on your One-Page Summary. Write out all the steps of your solution, especially when the question involves structures.

Example of a One-Page Summary

Chapter: Alkynes

1. IUPAC Naming: drop the -ane of alkane name and add –yne.
2. Physical properties: increasing () the number of carbons increases boiling point (bp), branching decreases boiling point, alkynes are not polar.
3. The two carbons (C) of the triple bond are sp hybridized, linear shape, bond angle = 180°.
4. Classified as internal, C-C≡C-C, or terminal, -C≡C-H
5. Terminal alkynes are slightly acidic:
   
6. Alkynide ions also react with carbonyl compounds:
   
7. Synthesis of Alkynes: - list and show the methods
8. Reactions of Alkynes: - list and show the reactions

Start off by memorizing just the eight points of this chapter: naming, physical properties, hybridization, classifications, terminal are acidic, alkynide ions, synthesis, reactions. Then memorize the important facts about those eight points.

http://helpmewithchemistry.com/studyguide

Cornell Format

http://muskingum.edu/~cal/database/content/genscience4.html

Working in the Laboratory

Here are some tips for working in the laboratory (C. Krause, CAL).

• Don't trust your memory. Write down everything you think might be pertinent. If you don't have time to take notes during lab, write down the most important information immediately after class.
• Make a permanent record of your observations. Use your own words and descriptions so you will remember exactly what you observed. Keep the lab record in a notebook separate from the lecture notebook. Start your record of each lab session on a new page, headed with the date.
• Organize the recorded data. Arrange the data so that it will be clear and fully labeled for later reference.
• Don't trust yourself or the apparatus too much. Do at least an approximate analysis (including rough graphs) of the data while they are being taken so you can detect anything that is going wrong in time to do something about it. Don't wait until after lab is over.
• Baby the apparatus. Make notes of its limitations and watch it for signs of strange behavior.
• Don't start the experiment or analysis until you clearly understand the objectives and procedures. Keep the purpose of the experiment in mind.
• Write up your reports clearly, legibly, and concisely in the proper format. Illustrations should be rendered clearly and labeled. Do the write-up as soon after the lab as possible, while the information is fresh in your mind. It is customary to use the passive voice in a lab report. Include such things as: purpose, background theory, apparatus, procedure, results, and conclusions. The latter usually includes an assessment of accuracy and possible sources of error.

http://muskingum.edu/~cal/database/content/genscience5.html

Chem Matrics

http://muskingum.edu/~cal/database/content/chemistry2.html

Chem Flowchart

http://muskingum.edu/~cal/database/content/chemistry2.html