Perbromate ion Lewis Structure

Perbromate ion Lewis Structure: BrO^4- Lewis Structure, tetrahedral Geometry, sp3 Hybridization & Polarity

Perbromate ion Key Facts

The Perbromate ion Lewis structure is Br–O single bond, Br–O double bond, Br–O double bond and Br–O double bond; the central Br has 4 electron domains (0 lone pairs), giving a tetrahedral electron-domain arrangement and a tetrahedral molecular geometry with a 109.5° bond angle. Br is best described as sp3-hybridized, and Perbromate ion is nonpolar because the bond dipoles cancel by molecular symmetry.

Figure 1: Lewis Structure of Perbromate ion (BrO^4-)

Chemical Formula	BrO4-
CAS Number	16474-32-1
Net Charge	-1
Total Valence Electrons	32
Lewis Structure	Br–O single bond, Br–O double bond, Br–O double bond and Br–O double bond
Electron-Domain Geometry	tetrahedral
Molecular Geometry	tetrahedral
Hybridization Model	sp3 (central Br)
Bond Angle	109.5°
Polarity	Nonpolar molecule

PubChem (CID 5460630) and NIST list Perbromate ion as BrO ^4- with CAS 16474-32-1; molecular weight ≈ 143.90 g/mol. View CAS 16474-32-1 dictionary details on Guidechem →

Applications of Perbromate ion (CAS 16474-32-1)

In aqueous and process chemistry, BrO^4- exists as the anion Perbromate ion ion. It is encountered as a counterion and a controlled source of Br in salts, buffers, electrochemistry and analytical protocols, and as a reactant in syntheses that require a defined equivalent of Br-containing material.

Step 1 - Valence Electrons & Central Atom

To draw the Perbromate ion Lewis structure we first count the total valence electrons. BrO^4- contains 7 (Br) + 4×6 (O) − 1 (net anion); the net charge of -1 gives a total of 32 valence electrons to place.

The central atom is Br. 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).

Step 2 - Lewis Structure & Electron Distribution

Place Br 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: Br–O single bond, Br–O double bond, Br–O double bond and Br–O double bond; no lone pairs on Br.

Counting bonding and nonbonding electrons around Br 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 Br–terminals bonds are equivalent in the resonance hybrid.

Step 3 - VSEPR Theory & Geometry

VSEPR theory states that the 4 electron domains around Br arrange to minimize mutual repulsion, giving an tetrahedral 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 tetrahedral; the Br bond angle is set to 109.5° rather than the ideal value for the electron-domain geometry.

Hybridization & Formal Charge

In the conventional localized-bond model, Br uses sp3 hybrid orbitals to form the 4 equivalent electron-domain directions (4 bonding + 0 lone pair).

Is Perbromate ion Polar or Nonpolar?

Perbromate ion is nonpolar. Although individual Br–terminal bonds are polar when the atoms differ in electronegativity, the tetrahedral geometry makes their vector sum zero, so there is no net molecular dipole.

Its nonpolar character governs solvation and intermolecular behavior; specify grade and handling when sourcing.

Structural Comparison Table

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