A) Total Lone Pairs in the Ion: The nitrite ion (NO2–) has a total of 2 lone pairs of electrons. In the Lewis structure of nitrite, nitrogen is bonded to two oxygen atoms. One of the oxygen atoms has a lone pair of electrons, and the other has three. The nitrogen also holds no lone pairs, resulting in two total lone pairs in the ion.
B) Molecular Shape of the Ion: The molecular shape of the nitrite ion is bent or V-shaped. This arises due to the presence of the lone pairs on oxygen, which repel the bonding pairs of electrons between nitrogen and oxygen. According to the VSEPR (Valence Shell Electron Pair Repulsion) theory, the lone pairs and bond angles create a geometry that results in a bent shape.
C) Resonance Structures: There are two resonance structures that can be drawn for the nitrite ion. These structures differ in the placement of the double bond between nitrogen and oxygen. The electron pairs can be redistributed between the nitrogen and the two oxygen atoms, resulting in these two contributing structures. Both structures equally contribute to the resonance hybrid of the nitrite ion.