Polarity of AsCl5 (trigonal bipyramidal)

[205743684]

Hi, I keep trying to understand why the dipole moments of AsCl5 cancel out but can't get my head around it because there is an odd number of things attached to the central atom and no lone pairs. That makes it trigonal bipyramidal but doesn't that mean there is more pull where the 3 Cl atoms are and less where the 2 Cl atoms are?

[Zinnia Kwan 3D]

No, it is nonpolar because technically the trigonal bipyramidal is a symmetrical structure, so the dipole moments all cancel out with each other.

[Emma Goellner 2I]

AsCl5 is a nonpolar molecule because there is no net dipole moment. The electron density is being pulled towards each Cl, which is more electronegative than As. Since all 5 elements bonded to the central atom are the same, and it is trigonal bipyramidal, there is no net dipole, and the molecule is nonpolar. It might help to draw arrows representing the separation of charge on the Lewis Structure as well :)

[Joshua Lee 3C]

No, the molecule would be nonpolar in this case due to geometry. Although there is an odd number of regions of electron density, the pulls would cancel out. This is because the three Cl atoms are at 120 angle degrees from one another, which would cancel each other out on the horizontal plane. The remaining two CL atoms are at 180 degrees to each other and thus cancel each other out because they pull in opposite directions. Thus, they all cancel, resulting in a nonpolar molecule.