AsO43-

[Agustina Santa Cruz 2F]

How is AsO43- a nonpolar molecule if it has a charge?

[Izamary Marquez 2H]

It helped me to draw out the dipole arrows! You will see that they point in opposite directions, which cancel out the distribution!

[dana hu 1B]

because all 4 of the oxygen surrounding As is canceling out each individual vectors, therefore it is nonpolar.

[Molly Posta 1H]

I think this is because even though there is a negative charge, there is no net dipole, so the molecule isn't polar. Dipole moment is a measure of polarity of a molecule, so that's what I look at when determining whether a molecule is polar, rather than looking at the overall charge for that molecule.

[Tam Nguyen 2B]

The -3 is to indicate the additional electrons and the formal charge of the overall molecule. The most stable structure of AsO4 3- is in the form of a tetrahedral. Although the bonds are polar, all the oxygens are equidistant from each other and have resonance, meaning that the compound itself is nonpolar.

[Alex Benson]

It is a nonpolar molecule because it has charges in opposing directions that cancel each other out!

[Mackenzie Van Val 3E]

AsO43- has a symmetric distribution of O around the central As, and all four atoms surrounding As are the same and thus will have the same electronegativity (and the same dipole moment with As). Therefore, the dipole moments between the As and each O will cancel out. Drawing the dipole arrows on the Lewis structure can be very helpful for seeing this. Hope this helps!

[Alan Huang 1E]

To find polarity of a molecule, you should check only electronegativity.

In the case of AsO4 3-, the molecule is nonpolar when you look at the predominant resonance structure. The molecule is tetrahedral and has a dipole moment because of the difference in electronegativities between arsenic and oxygen, but it cancels out.

[Aria Movassaghi 1A]

The charges cancel out so there is no net dipole moment.

[DominicMalilay 1F]

Even though it is an ion, the charges cancel so it is nonpolar.