1. SDN Mobile is now free on iTunes and on the Google Play Store. Enjoy!
    Dismiss Notice
  2. Dismiss Notice
  3. This forum is for support and discussion only. Please promote test prep materials/services (including AMAs) in the Special Offers subforum only. Thanks!
    Dismiss Notice
  4. Guest, be sure to check out How To Get Into Dental School, our free downloadable PDF with step-by-step details for dental school applicants!
    Dismiss Notice

Positive and negative in destroyer answer choice

Discussion in 'DAT Discussions' started by vvvv, Jun 5, 2008.

  1. vvvv

    2+ Year Member

    Joined:
    May 12, 2007
    Messages:
    119
    Likes Received:
    0
    Status:
    Pre-Dental
    in ochem I saw couple questions that have +- in front of the products. what do they mean by that? anybody knows?
     
  2. Mstoothlady2012

    5+ Year Member

    Joined:
    Apr 7, 2007
    Messages:
    1,714
    Likes Received:
    4
    Status:
    Dental Student
    for example........?
     
  3. creative8401

    creative8401 Im Anush Hayastan
    2+ Year Member

    Joined:
    Jan 22, 2008
    Messages:
    202
    Likes Received:
    2
    Status:
    Pre-Dental
    Hi. I’ve seen that one too. For example, in question 29, we see a +- sign, and from my understanding, this is used to show enantiomers of the product. For example, when we are dealing with BH3, THF, with H2O2 and OH-, the product is syn addition of OH and H. Thus, it can add cis and trans to the product. In a much deeper understanding, it refers to the plane of polarized light. Such things are determined experimentally, but it means that one bends light clockwise and the other counterclockwise.
    :)
     
  4. DDSguyLA

    2+ Year Member

    Joined:
    Mar 12, 2008
    Messages:
    386
    Likes Received:
    0
    Status:
    Pre-Dental
    well said
     
  5. TheWiredNerv

    2+ Year Member

    Joined:
    Aug 2, 2007
    Messages:
    1,394
    Likes Received:
    2
    Status:
    Pre-Dental
    To put it simply, + and - refers to the way light is polarized by the product.
     
    Stop hovering to collapse... Click to collapse... Hover to expand... Click to expand...
  6. creative8401

    creative8401 Im Anush Hayastan
    2+ Year Member

    Joined:
    Jan 22, 2008
    Messages:
    202
    Likes Received:
    2
    Status:
    Pre-Dental
    Hi everyone. You have to excuse sometimes my lengthy explanations to some of the questions, but since I don't know how much of an understanding a person has for the concepts, I structure my answers to build from the basics and develop a deeper understanding for the concepts. :)
     
  7. smile101

    2+ Year Member

    Joined:
    Dec 4, 2007
    Messages:
    401
    Likes Received:
    0
    Status:
    Pre-Dental
    You better know which rxns give enatiomers and and which ones give meso or optically active compounds when reacted. They certainly show up on the test.
     

Share This Page