Sodium amide Lewis Structure

Sodium amide Lewis Structure: H₂NNa Lewis Structure, bent Geometry, sp3 Hybridization & Polarity

Sodium amide Key Facts

The Sodium amide Lewis structure is 2 N–H single bond; the central N has 4 electron domains (2 lone pairs), giving a tetrahedral electron-domain arrangement and a bent molecular geometry with a ≈104.5° bond angle. N is best described as sp3-hybridized, and Sodium amide is polar because the bent shape (and/or unequal terminal atoms) prevents cancellation of the bond dipoles.

Figure 1: Lewis Structure of Sodium amide (H₂NNa)

Chemical Formula	H₂NNa
CAS Number	7782-92-5
Total Valence Electrons	8
Lewis Structure	2 N–H single bond
Electron-Domain Geometry	tetrahedral
Molecular Geometry	bent
Hybridization Model	sp3 (central N)
Bond Angle	≈104.5°
Polarity	Polar molecule

PubChem (CID 24533) and NIST list Sodium amide as H ₂NNa with CAS 7782-92-5; molecular weight ≈ 39.013 g/mol. View CAS 7782-92-5 dictionary details on Guidechem →

Applications of Sodium amide (CAS 7782-92-5)

As a hydride of N, Sodium amide 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.

Reducing Agent Electron-rich hydrides reduce metal centers and functional groups in synthesis.

Precursor / Feedstock Source of N in the preparation of derivatives and doped materials.

Handling Often toxic/flammable/pyrophoric; inert atmosphere and active ventilation required.

Procurement Note "Sodium amide" is supplied in multiple commercial grades and package sizes. Specify purity, grade, moisture/impurity limits, package (cylinder, drum or bulk) and intended process, and use CAS 7782-92-5 as the primary identifier when screening suppliers; always confirm regional availability and safety documentation (SDS).

Step 1 - Valence Electrons & Central Atom

To draw the Sodium amide Lewis structure we first count the total valence electrons. H₂NNa contains 2×1 (H) + 5 (N) + 1 (Na); the net charge of 0 gives a total of 8 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).

Valence-electron count

Total valence electrons = 2×1 (H) + 5 (N) + 1 (Na) = 8 electrons.

Step 2 - Lewis Structure & Electron Distribution

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: 2 N–H single bond; 2 lone pairs on N.

Counting bonding and nonbonding electrons around N therefore satisfies the octet/expanded-octet requirement for the drawn structure.

N–H ×2

N: 2 lone pairs, 2 bonding domains

2 bonding domains + 2 lone pairs = 4 electron domains

Octet Rule: Why N Has Eight Electrons N forms 2 bond(s) and retains 4 nonbonding electron(s), reaching an octet. No expanded octet is required for this second-row (or octet-satisfying) central atom.

Step 3 - VSEPR Theory & Geometry

VSEPR theory states that the 4 electron domains around N arrange to minimize mutual repulsion, giving an tetrahedral electron-domain geometry.

Because 2 of these domains are lone pair(s) — and lone pairs repel more strongly than bonding pairs — the observed molecular geometry is bent; the N bond angle is set to ≈104.5° rather than the ideal value for the electron-domain geometry.

Repulsion hierarchy

A useful VSEPR approximation is: lone pair–lone pair repulsion > lone pair–bonding pair repulsion > bonding pair–bonding pair repulsion. With 2 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.

Hybridization & Formal Charge

In the conventional localized-bond model, N uses sp3 hybrid orbitals to form the 4 equivalent electron-domain directions (2 bonding + 2 lone pair).

Formal-charge check

Formal charge on central N = V − N − ½B = 5 − 4 − ½×4 = 1. The nonzero formal charge is distributed by resonance / charge separation; the drawn structure is the lowest-energy contributor.

Modeling Note Modeling Note: sp3 is a compact model for the 4 electron-domain directions around N; full quantum-chemical treatments use molecular orbitals.

Is Sodium amide Polar or Nonpolar?

Sodium amide is polar. The bent shape prevents cancellation of the bond dipoles. The bond dipoles do not cancel, leaving a net molecular dipole, which strongly influences solvation behavior and intermolecular interactions.

Expert Quote — Structural Chemistry Perspective

The decisive structural fact is not simply that the individual bonds are polar; it is whether molecular symmetry allows their vector sum to vanish. In Sodium amide the bent arrangement prevents cancellation, so a permanent dipole remains.

Interpretation consistent with standard VSEPR / molecular-geometry references.

This polarity profile underpins its behavior as a solvent, reactant or process intermediate; when sourcing, specify grade and container compatibility.

Structural Comparison Table

Species	Formula	Central Atom	Electron Domains	Molecular Geometry	Polarity
Sodium amide	H₂NNa	N	4	bent	Polar
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

Practice question Starting from the 8 valence electrons of H₂NNa, draw the Lewis structure and confirm the central N atom is sp3-hybridized with bent geometry. What happens to the bond angle if one terminal atom is replaced by a more electronegative substituent?

Looking for industrial bulk or specified-grade supplies of Sodium amide (CAS 7782-92-5)? Browse Supplier on Guidechem →

FAQs

Is H₂NNa polar or nonpolar?

Sodium amide is polar. Its bent geometry (and/or unequal terminal atoms) stops the bond dipoles from cancelling.

What is the Lewis structure of Sodium amide?

2 N–H single bond; 2 lone pairs on N. It uses all 8 valence electrons and the preferred structure carries a formal charge of 1 on the central atom.

What is the bond angle in Sodium amide?

The N angle is about ≈104.5°. Lone-pair repulsion compresses the angle from the ideal tetrahedral value.

What is the hybridization of N in Sodium amide?

The conventional model is sp3. Sodium amide has 4 electron domains around the central N.

What is the CAS number of Sodium amide?

The CAS number is 7782-92-5. PubChem (CID 24533) and NIST identify this with H₂NNa; use it to locate suppliers and database records.

References

PubChem CID 24533, Sodium amide. Molecular formula, CAS number, molecular weight and chemical identity.
NIST Chemistry WebBook, SRD 69, Sodium amide. Formula, CAS Registry Number and thermochemical / spectroscopic data.
IUPAC Gold Book. Definitions for "lone pair", "VSEPR", "hybridization" and "formal charge".
Atkins, P. & de Paula, J., Physical Chemistry. VSEPR, molecular geometry and dipole moments.
Guidechem supplier & dictionary records. Commercial sourcing and CAS-linked property pages for Sodium amide (CAS 7782-92-5).

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 7782-92-5 identifies the substance, not a universal purity specification.

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Sodium amide Lewis Structure