2011 Ochem Lab Exam 1

2011 Ochem Lab Exam - CHEM 3112 Exam 1 M arch 8 2011 Name TA(Circle one Todd Derek Gerard Tapash 8 Travis Madhavi Gaumani Sathish Keep y our

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.. CHEM 3112 Exam 1 March 8, 2011 Name TA (Circle one) Todd Tapash Madhavi Derek 8 Gaumani Gerard Travis Sathish Keep your answers short! For credit, SHOW ALL OF YOUR WORK! It is expected that the atomic masses of C, H, and a are known at this point in semester. IR and NMR tables are provided on last page. This page may be detached.
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Multiple Guess 1. Which of the fOlioWin~est polarity? methanol hexane acetone water 2. Choosing a solvent for recrystallization, ideally the product should be ____ _ 4 Soluble in the solvent )if More dense than water c) Insoluble in the solvent @soluble in the solvent only when heated ".,.,,Xj ~,~ ~ ~~~, . . ~'t. ,.. ¥,';y.~~" 3. Which 2 protons are in the same chemical environment (are chemically equivalent)? i and ii i and iv and iii 4. What is reason MgS04 in several experiments? @)s a drying ag.ent to remove trace amounts from an organic solvent. b) During extractions, it pulls molecules from the organic layer and helps force the organic compounds into the organic layer. To separate the organic compounds the inorganic salts. d) convert the benzoic acid benzoate ion, which partitions into the aqueous layer. 5. Which the following chemicals will elute last from a chromatography column? Explain basis your choice. (, 'V d CH2C1 < }-CH20H w !'-1d f-t /!'t?(#1;'\ \~ 6. Compound A shows the following solubility data: 0.32 gl100 mL H 2 0 at 5°C 6.44 mL H 2 0 at 100°C. What is the theoretical recovery in the first crop from a solution 4.68 g A in 75.0 H 2 0 cooled to 5°C? 4.36g ~ 4.S1g l. 31. . ) . 7 ~ -:., I.- y 4.S9g
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\ 7. What splitting pattern in the lH NMR spectrum would you expect for designated hydrogen atom(s) in the compounds shown below? Select your answer from listed choices. H Br-Q-No, H Triplet Quartet Quintet ~ inlet Do et riplet Hextet uartet Singlet Doublet
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top Separation theory Complete the following flowchart to show how three compounds could be separated by chemically active extraction. Fill in blanks and boxes. The boxes should contain the structures of the compounds as they would exist in solution at that point the extraction process. Don't forget show ions where necessary. I 0 yr OH ~ ~OH ~/ayer dissolve in eth~ top extract with :., b tt Loom rJ 7' " I "" ~ layer ~O\!! ~ 1 ' - +(. .1 o--,,\"f extract with I\)Pl() 1-/ add IV :J- ,7 ~ bottom (1 ~ow % if + lJ.,LI 1- 111-" ifppt, if no ppt, dry with I"'~ $ 0 ,., add i- ~ evaporate ;r )IJ( (? ~ll?tI if ppt, k"Ure;d ifno ppt, I ~~,,~{i tr
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Practical Tips and Tidbits o 1 A. What causes the pressure build up during an extraction? c--'--t-t\. ..:u. .ls ree. ..-t:""'9 ""./fl" ~",l oJl.~ ... .¢'t""J ~l:~ ~.,. .(eow ,:Jr.;>J/;,.Jf B. During an extraction, what is most common cause for layers not draining quickly?
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This note was uploaded on 03/25/2012 for the course CHEM 3112 taught by Professor Staff during the Spring '11 term at Oklahoma State.

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2011 Ochem Lab Exam - CHEM 3112 Exam 1 M arch 8 2011 Name TA(Circle one Todd Derek Gerard Tapash 8 Travis Madhavi Gaumani Sathish Keep y our

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