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Homework Help: Polar molecule

  1. Mar 26, 2008 #1
    A diatomic molecule XY that contains a polar bond must be a polar molecule. A triatomic molecule XY2 that contains a polar bond does not necessarily form a polar molecule. I need some examples of real molecules to help me explain the difference.

  2. jcsd
  3. Mar 26, 2008 #2


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    Look at CO2
  4. Mar 26, 2008 #3
    concentration of hydrogen ions

    oops...posted wrong message:(
    Last edited: Mar 26, 2008
  5. Mar 26, 2008 #4
    so you are saying to look at CO2 as an example?
  6. Mar 26, 2008 #5

    That's what he/she said.
  7. Mar 26, 2008 #6
    so I guess my question should become a little more specific...can someone tell me how (or give me a website) CO2 demonstates this?!
  8. Mar 26, 2008 #7
    Look at CO2, compare it to H2O.
  9. Mar 27, 2008 #8
    CO2 = :O::C::O:

    H2O = H::O::H

    So I compared them this way, but am I using the right method for this problem? I know that H2O is a polar covalent bonds forming a polar covalent molecule. But carbon is my center in CO2, not oxygen as it is in H2O. Help:(

    edit: my dots are suppose to be over the carbon to represent non bonded pairs...
  10. Mar 27, 2008 #9
    hint: CO2 is linear and H2O is bent

    a molecule is polar when it has a side with a partial negative charge and the opposite side with a partial positive charge.

    try to locate these partial charges on the molecules.
  11. Mar 27, 2008 #10
    H2O does not have any double bonds, BTW; its electron distribution is why it's a different shape to CO2 (as Kushal pointed out). Only vaguely related to the question, but an important concept.
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