-
We detected your language preference as English. Would you like to switch to the English version for a better experience?
Switch to English
Stay here
The Nitric acid Lewis structure is N–O double bond, N–O single bond and N–O single bond; the central N has 3 electron domains (0 lone pairs), giving a trigonal planar electron-domain arrangement and a trigonal planar molecular geometry with a 120° bond angle. N is best described as sp2-hybridized, and Nitric acid is nonpolar because the bond dipoles cancel by molecular symmetry.
Figure 1: Lewis Structure of Nitric acid (HNO3)
| Chemical Formula | HNO3 |
| CAS Number | 7697-37-2 |
| Total Valence Electrons | 24 |
| Lewis Structure | N–O double bond, N–O single bond and N–O single bond |
| Electron-Domain Geometry | trigonal planar |
| Molecular Geometry | trigonal planar |
| Hybridization Model | sp2 (central N) |
| Bond Angle | 120° |
| Polarity | Nonpolar molecule |
As a hydride of N, Nitric acid is typically a strong reducing agent, a potential fuel component, or a precursor in inorganic and organometallic synthesis. Many pnictogen/sulfur hydrides are toxic, foul-smelling and pyrophoric or flammable, and are handled with appropriate ventilation and inert-atmosphere technique.
To draw the Nitric acid Lewis structure we first count the total valence electrons. HNO3 contains 1 (H) + 5 (N) + 3×6 (O); the net charge of 0 gives a total of 24 valence electrons to place.
The central atom is N. It is the least electronegative atom capable of forming multiple bonds and is surrounded by the more electronegative terminal atom(s); hydrogen, when present, always occupies a terminal position. Electronegativity considerations place the electron density toward the terminal atom(s).
Total valence electrons = 1 (H) + 5 (N) + 3×6 (O) = 24 electrons.
Place N at the center and connect each surrounding atom with a single bond, complete octets on the terminal atoms, and place any remaining electrons on the central atom. The resulting electron distribution is: N–O double bond, N–O single bond and N–O single bond; no lone pairs on N.
Counting bonding and nonbonding electrons around N therefore satisfies the octet/expanded-octet requirement for the drawn structure.
This species is best represented by resonance structures; the π bonding is delocalized over the equivalent terminal atom(s), so all N–terminals bonds are equivalent in the resonance hybrid.
VSEPR theory states that the 3 electron domains around N arrange to minimize mutual repulsion, giving an trigonal planar electron-domain geometry.
Because 0 of these domains are lone pair(s) — and lone pairs repel more strongly than bonding pairs — the observed molecular geometry is trigonal planar; the N bond angle is set to 120° rather than the ideal value for the electron-domain geometry.
A useful VSEPR approximation is: lone pair–lone pair repulsion > lone pair–bonding pair repulsion > bonding pair–bonding pair repulsion. With 0 lone pair(s) on N, the lone-pair domains occupy positions that minimize overall repulsion while pushing the bonding domains (and therefore the bonded atoms) closer together.
In the conventional localized-bond model, N uses sp2 hybrid orbitals to form the 3 equivalent electron-domain directions (3 bonding + 0 lone pair).
Formal charge on central N = V − N − ½B = 5 − 0 − ½×8 = 1. The nonzero formal charge is distributed by resonance / charge separation; the drawn structure is the lowest-energy contributor.
Nitric acid is nonpolar. Although individual N–terminal bonds are polar when the atoms differ in electronegativity, the trigonal planar geometry makes their vector sum zero, so there is no net molecular dipole.
A common misconception is that polar bonds guarantee a polar molecule. Nitric acid shows the opposite: identical bond dipoles arranged with trigonal planar symmetry cancel exactly, yielding a nonpolar species.
Interpretation consistent with standard VSEPR / molecular-geometry references.Its nonpolar character governs solvation and intermolecular behavior; specify grade and handling when sourcing.
| Species | Formula | Central Atom | Electron Domains | Molecular Geometry | Polarity |
|---|---|---|---|---|---|
| Nitric acid | HNO3 | N | 3 | trigonal planar | Nonpolar |
| Ammonia | H3N | N | 4 | trigonal pyramidal | Polar |
| Ammonium | H4N | N | 4 | tetrahedral | Nonpolar |
| Hydrazine | H4N2 | N | 4 | trigonal pyramidal | Polar |
| Nitrogen | N2 | N | 2 | linear (diatomic) | Nonpolar |
| Nitric oxide | NO | N | 3 | linear (diatomic) | Polar |
Nitric acid is nonpolar. Its trigonal planar symmetry cancels the bond dipoles exactly.
N–O double bond, N–O single bond and N–O single bond; no lone pairs on N. It uses all 24 valence electrons and the preferred structure carries a formal charge of 1 on the central atom.
The N angle is about 120°. Lone-pair repulsion compresses the angle from the ideal trigonal planar value.
The conventional model is sp2. Nitric acid has 3 electron domains around the central N.
The CAS number is 7697-37-2. PubChem (CID 944) and NIST identify this with HNO3; use it to locate suppliers and database records.
Technical scope: Lewis structures, VSEPR and hybridization are model-based descriptions for chemical communication and structure prediction; actual molecular electronic structure is more accurately represented by molecular-orbital and quantum-chemical methods. Commercial grades vary substantially by supplier and intended use; CAS 7697-37-2 identifies the substance, not a universal purity specification.
 |
|
 |
EN
Agricultural News
Food News
Industrial News
Cosmetic News
Pharmaceutical News
Science News
