another ochem

Discussion in 'DAT Discussions' started by allstardentist, Jul 26, 2006.

  1. allstardentist

    allstardentist All-Star

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    Which of the following is most easily oxidized?
    A. R—COOH
    B. R2C=O
    C. R—CHO
    D. R2CH—OH
    E. R3C—OH
     
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  3. Shane41

    Shane41 Member

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    pretty sure primary alcohols are oxidized easiest. I dont even think tertiary can be oxidized
     
  4. jackbauer!

    jackbauer! Guest

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    the answer is D.
     
  5. allstardentist

    allstardentist All-Star

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    the answer is C. My guess is because of steric hindrance. Anyone have thoughts on this problem?
     
  6. Uracil

    Uracil Member

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    I think aldehydes are the most easily oxidized because they can be oxidized by many oxidizing agents compared to others?
     
  7. dental#1

    dental#1 Fla DDS

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    I also agree that the answer is C. 1st it is an aldehyde and 2nd there is no steric strain. Answer A and B are Carbo acids so they are there ruled out.... C,D and E are all primary alcohol however, D is attached to 2R sub. on the Carbon and 3R sub. on the Carbon for E. Hope this clears it up!
     
  8. jackbauer!

    jackbauer! Guest

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    C is an aldehyde, D is a tertiary alcohol, and E is a quaternary alcohol.

    gl with the dat,
    jb!
     
  9. tom_servo_dds

    tom_servo_dds Senior Member

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    C is an aldehyde, D is a secondary alcohol, and E is a tertiary alcohol. You name alcohols based on the carbon substitution. So if it's an alcohol attached to a tertiary carbon, it will be a tertiary alcohol. Amines on the other hand are named based on their own attachments, not the carbon that they may be attached to. So a Nitrogen with two attached R groups will be a secondary amine, three attached R groups, tertiary amine.

    http://en.wikipedia.org/wiki/Alcohol#Primary.2C_secondary.2C_and_tertiary_alcohols
    http://en.wikipedia.org/wiki/Amine

    FYI, B is a Ketone, not a carboxylic acid. Tertiary alcohols can be oxidized, but resist it.

    Best of luck!
     
  10. dental#1

    dental#1 Fla DDS

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    I am so sorry it was late! B is a ketone my bad. I guess I better get on it!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
     
  11. jackbauer!

    jackbauer! Guest

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    sorry that's what i meant. the answer is still D, a secondary alcohol is the easier to oxidize than an aldehyde.
     
  12. dental#1

    dental#1 Fla DDS

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  13. issa

    issa Senior Member

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    good question. i learned something new.
     
  14. allstardentist

    allstardentist All-Star

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    The real answer is C not D according to kaplan.
     
  15. jackbauer!

    jackbauer! Guest

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    think about it.... the less a compound is oxidized the easier it is to oxidize it....it's pretty common sense.

    jb!
     
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  17. slayerdeus

    slayerdeus Member

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    I don't think you get it jack. All-star has the answers and it is C because of the steric hinderance exhibited by D, otherwise D would be your answer if there was only 1R groups connected instead of 2.
     
  18. mellon977

    mellon977 Member

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    Shouldn't it be D since primary alcohols more readily oxidize to aldehydes? This is an Orgoman question!
     
  19. mellon977

    mellon977 Member

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    After hard searching, the answer is C! Since the aldehyde already has the carbonyl function group, it oxidizes more at ease than the alcohols do
     
  20. desert

    desert Junior Member

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    agree

    Desert
     
  21. RING12

    RING12 Member

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    i just finished ochem last semester. i can tell you that the answer is primary alcholo. whenever you stuck in any porblem that ask about oxidiation ask yourself which one can make for O.it can be aldehyde b/c still have to oxidize to oxygen till become carboxylic acid to have the maxium o. the the answer is D.
     
  22. allstardentist

    allstardentist All-Star

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    D is not a primary alcohol if you look at it carefully.
     
  23. lemoncurry

    lemoncurry tequila mockingbird
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    D is definitely not a primary, but a secondary.
     
  24. cryptozoologist

    cryptozoologist Junior Member

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    i'm taking ochem this summer and my professor said it was a bogus poorly worded question...because the "most easily oxidized" doesn't have meaning in Organic chemistry without crisp detailed assumptions regarding solvents, nucleophiles, electrophiles, environment, etc.

    He said he could drum up experimental conditions that would make every answer the "easiest to oxidize".

    I secondarily did a fair search of online material looking for "easiest to oxidize" etc. I found no clear cut statement which would of course support my professors position. So I wouldn't sweat it too much.
     
  25. mellon977

    mellon977 Member

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    First of all, not every question has a "clear cut" answer however there is a "major" principle reflected in the answer. I believe the question is eluding to the oxidation levels of the functional groups. The reasoning for my answer is the fact that the aldehyde, when oxidized will be a carboxylic acid

    (Note, oxidation is defined as a reaction that introduces a more electronegative element to or removes a molecular H from the system.)

    On the other hand, the secondary alcohol in D can only be oxidized to a ketone.

    Looking at the oxidation levels between both fxnal groups, the aldehyde is "easily" oxidized to become a more oxidative group than the ketone.
     

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