Arsenide ion Lewis Structure

Arsenide ion Lewis Structure: As Lewis Structure, see text Geometry, sp3 Hybridization & Polarity

Arsenide ion Key Facts

The Arsenide ion Lewis structure is central As bonded; the central As has 4 electron domains (4 lone pairs), giving a tetrahedral electron-domain arrangement and a see text molecular geometry with a — bond angle. As is best described as sp3-hybridized, and Arsenide ion is polar because the see text shape (and/or unequal terminal atoms) prevents cancellation of the bond dipoles.

Figure 1: Lewis Structure of Arsenide ion (As)

Chemical Formula	As
CAS Number	22541-49-9
Net Charge	-3
Total Valence Electrons	8
Lewis Structure	central As bonded
Electron-Domain Geometry	tetrahedral
Molecular Geometry	see text
Hybridization Model	sp3 (central As)
Bond Angle	—
Polarity	Polar molecule

PubChem and NIST list Arsenide ion as As with CAS 22541-49-9; molecular weight ≈ None g/mol. View CAS 22541-49-9 dictionary details on Guidechem →

Applications of Arsenide ion (CAS 22541-49-9)

In aqueous and process chemistry, As exists as the anion Arsenide ion ion. It is encountered as a counterion and a controlled source of As in salts, buffers, electrochemistry and analytical protocols, and as a reactant in syntheses that require a defined equivalent of As-containing material.

Ion Source / Counterion Supplied as salts and solutions; specify hydration, counter-cation and concentration.

Analytical & Electrochemical Used in titrations, plating baths and ionic-strength control where the ion is the active species.

Synthesis Reagent A controlled source of As in precipitation, complexation and redox procedures.

Procurement Note "Arsenide ion" 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 22541-49-9 as the primary identifier when screening suppliers; always confirm regional availability and safety documentation (SDS).

Step 1 - Valence Electrons & Central Atom

To draw the Arsenide ion Lewis structure we first count the total valence electrons. As contains 5 (As) − 3 (net anion); the net charge of -3 gives a total of 8 valence electrons to place.

The central atom is As. 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 = 5 (As) − 3 (net anion) = 8 electrons.

Step 2 - Lewis Structure & Electron Distribution

Place As 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: central As bonded; 4 lone pairs on As.

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

As: 4 lone pairs, 0 bonding domains

0 bonding domains + 4 lone pairs = 4 electron domains

Octet Rule: Why As Has Eight Electrons As forms 0 bond(s) and retains 8 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 As arrange to minimize mutual repulsion, giving an tetrahedral electron-domain geometry.

Because 4 of these domains are lone pair(s) — and lone pairs repel more strongly than bonding pairs — the observed molecular geometry is see text; the As bond angle is set to — 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 4 lone pair(s) on As, 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, As uses sp3 hybrid orbitals to form the 4 equivalent electron-domain directions (0 bonding + 4 lone pair).

Formal-charge check

Formal charge on central As = V − N − ½B = 5 − 8 − ½×0 = -3. 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 As; full quantum-chemical treatments use molecular orbitals.

Is Arsenide ion Polar or Nonpolar?

Arsenide ion is polar. The see text 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 Arsenide ion the see text 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
Arsenide ion	As	As	4	see text	Polar
Arsenic trifluoride	AsF₃	As	4	trigonal pyramidal	Polar

Practice question Starting from the 8 valence electrons of As, draw the Lewis structure and confirm the central As atom is sp3-hybridized with see text 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 Arsenide ion (CAS 22541-49-9)? Browse Supplier on Guidechem →

FAQs

Is As polar or nonpolar?

Arsenide ion is polar. Its see text geometry (and/or unequal terminal atoms) stops the bond dipoles from cancelling.

What is the Lewis structure of Arsenide ion?

central As bonded; 4 lone pairs on As. It uses all 8 valence electrons and the preferred structure carries a formal charge of -3 on the central atom.

What is the bond angle in Arsenide ion?

The As angle is about —. Lone-pair repulsion compresses the angle from the ideal tetrahedral value.

What is the hybridization of As in Arsenide ion?

The conventional model is sp3. Arsenide ion has 4 electron domains around the central As.

What is the CAS number of Arsenide ion?

The CAS number is 22541-49-9. PubChem and NIST identify this with As; use it to locate suppliers and database records.

References

PubChem, Arsenide ion. Molecular formula, CAS number, molecular weight and chemical identity.
NIST Chemistry WebBook, SRD 69, Arsenide ion. 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 Arsenide ion (CAS 22541-49-9).

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 22541-49-9 identifies the substance, not a universal purity specification.

Make Guideview Preferred Source on Google

Arsenide ion Lewis Structure