Editing Nitrite (section)

== Structure ==
[[Image:Nitrite-ion-canonical-structures.svg|thumb|200px|class=skin-invert-image|The two [[Resonance (chemistry)#Resonance as a diagrammatic tool|canonical structures]] of {{chem|NO|2|-}}, which contribute to the resonance hybrid for the nitrite ion]]
[[File:Trans-nitrous-acid-2D-dimensions.png|thumb|200px|class=skin-invert-image|Dimensions of ''trans''-HONO (from the [[rotational spectroscopy|microwave spectrum]])]]
The nitrite ion has a symmetrical structure (C<sub>2v</sub> [[molecular point group|symmetry]]), with both N–O bonds having equal length and a bond angle of about 115°. In [[valence bond theory]], it is described as a [[resonance hybrid]] with equal contributions from two canonical forms that are mirror images of each other. In [[molecular orbital theory]], there is a [[sigma bond]] between each oxygen atom and the nitrogen atom, and a delocalized [[pi bond]] made from the [[p orbitals]] on nitrogen and oxygen atoms which is perpendicular to the plane of the molecule. The negative charge of the ion is equally distributed on the two oxygen atoms. Both nitrogen and oxygen atoms carry a [[lone pair]] of electrons. Therefore, the nitrite ion is a [[Lewis base]].

In the gas phase it exists predominantly as a ''trans''-planar molecule.