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Permanent dipole-dipole attraction between molecules - (CH3)2CO watch

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    1. In one of chemistry specimen paper,
    question asks to find which substance had the permanent dipole-dipole attraction out of following examples :
    - CCl4
    -C2F4
    -(CH3)2CO
    -CO2
    the answer was the third molecule.
    But doesn't the first one also have a dipole attraction?


    2. Also, how do you distinguish dipole-dipole bond in a compound in general, do you have to count every bond's attraction?

    Thanks a lot!
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    (Original post by ucjs2)
    1. In one of chemistry specimen paper,
    question asks to find which substance had the permanent dipole-dipole attraction out of following examples :
    - CCl4
    -C2F4
    -(CH3)2CO
    -CO2
    the answer was the third molecule.
    But doesn't the first one also have a dipole attraction?


    2. Also, how do you distinguish dipole-dipole bond in a compound in general, do you have to count every bond's attraction?

    Thanks a lot!
    1. All bonds joining atoms of different electronegativity make dipoles.
    2. Dipoles are vector quantities and can be resolved in three dimensions
    3. If the resolved vectors all cancel each other out in all three dmensions then the molecule is non -polar.
 
 
 
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