Dipole Dipole and Lewis Dot structes

[undertow]

Why doesn't HOOH dipole dipole forces?

I read that if a molecule has an Oxygen atom, it's likely to have dipole forces. This one only has Dispersion forces.

Also, why does the Lewis structure of this molecule NOT look like this:

 

[bomba923]

Because the dipoles cancel out. (e.g., $$CO_2$$ is nonpolar, but contains polar bonds).

The component dipole moments of $$H_2O_2$$ simply cancel out, and it has no net dipole moment.
You see, hydroxyl groups contain a partially positively charged hydrogen and a partially negatively charged oxygen.

Draw the direction of each dipole moment, and you will have two antiparallel H -|--> O equal in magnitude but opposite in direction (as vectors). As in vector addition, these two dipole moments will cancel each other out (you have a zero vector for net dipole).
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Also, why does the Lewis structure of this molecule NOT look like this:
http://img111.imagevenue.com/loc276/th_b0d_untitled.JPG

Consider formal charge, and the usual valence of oxygen atoms. (http://www.westga.edu/~chem/courses/chem1212slattery/contents/chapter8-all/img031.gif )
(Hint: Oxygen | $1 s ^2 2 s^2 2 p^4$ )

 

[ravenprp]

H-O-O-H

Dipole-dipole forces are attractive forces between polar molecules. These forces arise due to the uneven distribution of electrons in a molecule, resulting in a partial positive end and a partial negative end. In order for a molecule to exhibit dipole-dipole forces, it must have a permanent dipole moment.

In the case of HOOH (hydrogen peroxide), the molecule is polar due to the electronegativity difference between the oxygen and hydrogen atoms. However, the molecule does not have a permanent dipole moment because the two oxygen atoms are arranged in a non-linear fashion, canceling out the dipole moments of each individual bond. This results in the overall molecule having no net dipole moment and therefore, no dipole-dipole forces.

As for the Lewis dot structure, it does not look like H-O-O-H because the oxygen atoms are bonded to each other through a single bond, rather than a double bond. This is due to the repulsion between the lone pairs of electrons on the oxygen atoms, leading to a more stable structure with single bonds. Therefore, the Lewis dot structure of HOOH is H-O-O-H, with each oxygen atom having a lone pair of electrons instead of a double bond.