Numford
Lewis structure

Lewis structure of NO₂

17 valence electrons. One N=O double bond and one N-O single bond, with no lone pair on N and one odd electron, so N has only 7 electrons around it. 2 resonance structures.

ONO
  • N
  • O
  • odd electron

NO₂Nitrogen dioxide

Bent

AB₂E: 2 bond pairs, 1 odd electron

  • Hybridisationsp²
  • Bond angleabout 134°
  • Polaritypolar

Lewis structure

17 valence electrons, 2 resonance structures
i

An odd electron molecule: 17 valence electrons, so N has only seven around it.

NOO+−
NOO+−

Formal charges: N +1, O −1

Why this shape

  1. N has 5 valence electrons. In the Lewis structure it makes one double bond to O and one single bond to O and keeps no lone pair and one odd electron, which leaves it a formal charge of +1.
  2. Steric number = two sigma bonds + one odd electron = 3, so N is sp² hybridised. A double or triple bond counts once: only its sigma bond uses a hybrid orbital.
  3. Three electron domains point to the corners of a flat triangle (trigonal planar electron geometry). With one odd electron in place of atoms, the atoms make a bent shape.
  4. N has a single unpaired electron, not a lone pair. One electron repels the bonds less than a pair would, so the bond pairs push each other open to about 134 degrees.
  5. The bond dipoles do not cancel in the bent shape, so NO₂ is polar.
Working

How to draw it

  1. Count the valence electrons: N 5 + 2 × O 6 = 17 valence electrons (an odd number, so one electron stays unpaired).
  2. Put N in the middle and join it to the two outer atoms with single bonds.
  3. Give each outer atom lone pairs until it has an octet (H needs only two electrons), then put any electrons left over on the central atom.
  4. Where an atom is still short of an octet, turn a lone pair of its neighbour into a shared pair: that makes a double or triple bond.
  5. Result: one N=O double bond and one N-O single bond, with no lone pair on N and one odd electron, so N has only 7 electrons around it.
  6. Formal charge = valence electrons − lone pair electrons − number of bonds. Here: N +1, O −1.
  7. The double bond can sit in two equivalent ways, so there are two resonance structures. The real molecule is a hybrid of them.

Class 11, Chapter 4 Chemical Bonding and Molecular Structure.

Questions

Lewis structure of NO2: quick answers

How many valence electrons are in NO2?

N 5 + 2 × O 6 = 17 valence electrons (an odd number, so one electron stays unpaired).

What are the formal charges in the Lewis structure of NO2?

N +1, O −1; every other atom is zero. Formal charge = valence electrons - lone pair electrons - number of bonds.

How many resonance structures does NO2 have?

2. The double bond can sit in two equivalent ways, so there are two resonance structures. The real molecule is a hybrid of them.

Try any molecule