Draw the Lewis Structure for HNO3 and State Its Molecular Geometry: Is It Polar or Nonpolar?

To draw the Lewis structure for HNO₃ (nitric acid), follow these steps:

1. Determine the total number of valence electrons. Nitrogen (N) has 5 valence electrons, each oxygen (O) has 6, and hydrogen (H) has 1. So, the total is 5 + (3 × 6) + 1 = 24 valence electrons.
2. Place the least electronegative atom (hydrogen) in the center. However, in HNO₃, nitrogen is the central atom because it can form multiple bonds.
3. Connect the atoms with single bonds: H-O-N-O-O. This uses 8 electrons (4 bonds × 2 electrons).
4. Distribute the remaining electrons to satisfy the octet rule for each atom. Oxygen atoms need 6 more electrons each, and nitrogen needs 3 more electrons.
5. Form double bonds where necessary to satisfy the octet rule. In HNO₃, one of the oxygen atoms forms a double bond with nitrogen.

The final Lewis structure looks like this:

    O
    ||
H-O-N
    |
    O

Molecular Geometry: The molecular geometry of HNO₃ is trigonal planar around the nitrogen atom. The nitrogen atom is surrounded by three oxygen atoms, with one of them forming a double bond.

Polarity: HNO₃ is a polar molecule. The presence of the highly electronegative oxygen atoms and the asymmetrical shape of the molecule create a dipole moment, making it polar.