# Is hyponitrite polar or nonpolar?

Jun 30, 2016

...Both (but not at the same time).

The hyponitrite ion, ${\text{N"_2"O}}_{2}^{2 -}$, has a trans major resonance structure that looks like this:

But it also has a cis major resonance structure that looks like this:

Either way, oxygen is more electronegative than nitrogen, so there are two dipole moment vectors whose components will add to form a net dipole.

• Here, the two dipole moment vectors cancel out in the horizontal direction (along the $\text{N"="N}$ bond), but add in the vertical direction (perpendicular to the $\text{N"="N}$ bond), giving a nonzero net dipole.

• Here, the two dipole moment vectors cancel out in both the horizontal (along the $\text{N"="N}$ bond) and vertical (perpendicular to the $\text{N"="N}$ bond) directions, giving no net dipole.

Therefore, the cis isomer is polar, and the trans isomer is nonpolar.