Ap Chemistry- Unit 2

Electron Pair Geometry

Electron Pair Geometry

Electron Pair Geometry (EPG) is the arrangement of the electrons both bonded and lone pairs around a central atom.

Bonds will be usually pushed down if there’s a lone pair, because of electron repulsion.

Angles are exact no less than.

Molecular Geometry

The Molecular Geometry (MG) is the shape we can "see" of the molecule. This means that Molecular Geometry only describes the bonds of the molecule and does not describe the lone pair electrons.

Because in real life we do not see the lone pair, MG only describes the bonds as a result of the lone pair.

Angles are usually not exact uses less than frequently.

Linear

AX₂E₀

_{No lone pairs, and 180.}

_NP

_{Molecular and Electron-pair geometry}

_sp

Trigonal Planar

AX₃E₀

No lone pairs 120

NP

_{Molecular and Electron-pair geometry}

_sp²

Bent

AX₂E₁

_{One lone pair}

_P

_{less than 120}

_{Molecular Geometry is Bent}

_{Electron-Pair Geometry is Trigonal Planar}

_sp²

Tetrahedral

AX₄E₀

_{No lone pairs}

_NP

_109.5

_{Molecular and Electron-pair Geometry}

_sp³

Trigonal Pyramid

AX₃E₁

_{One lone pair}

_P

_{less than 109.5}

_{Molecular Geometry is Trigonal Pyramid}

_{Electron-pair Geometry is Tetrahedral}

_sp³

Bent

AX₂E₂

_{2 Lone pairs}

_P

_{Less than 109.5}

_{Molecular Geometry is Bent}

_{Electron-pair Geometry is Tetrahedral}

_sp³

Trigonal Bipyramid

AX₅E₀

No Lone pairs

NP

180, 120, and 90

Molecular and Electron-pair Geometry

sp³d

See-Saw

AX₄E₁

One lone pair

P

less than 180, 120, and 90

Molecular Geometry is See-Saw

Electron-pair Geometry is Trigonal Bipyramid

sp³d

T-Shaped

AX₃E₂

2 Lone pairs

P

Less than 180, and 90

Molecular Geometry is T-shaped

Electron-pair Geometry is Trigonal bipyramid

sp³d

Linear

AX₂E₃

3 Lone pairs

NP

180

Molecular geometry is linear

Electron-pair geometry is Trigonal bipyramid

sp³d

Octahedral

AX₆E₀

No lone pairs

NP

90

Molecular and Electron-pair geometry

sp³d²

Square Pyramid

AX₅E₁

One lone pairs

P

less than 90

Molecular geometry is Square pyramid

Electron-pair geometry is octahedral

sp³d²

Square Planar

AX₄E₂

2 Lone pairs

NP

90

Molecular geometry is Square planar

Electron-pair geometry is Octahedral

sp³d²