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CHEM 121 Studioby Learn4Less · UBC CHEM 121

CHEM 121 glossary

Square planar

The AX4E2\mathrm{AX_4E_2} shape: an octahedron with two lone pairs on opposite sides, leaving four atoms at the corners of a square around the centre, 90° apart.

Central Xe atom bonded to 4 F atoms, with 2 lone pairs.FFXeFF90°180°Ideal bond angles: 90°, 180°
XeFX4\ce{XeF4}: lone pairs above and below, four F atoms in a plane.

Example

IClX4X−\ce{ICl4-} and BrFX4X−\ce{BrF4-} are square planar. With identical outer atoms the four bond dipoles cancel, so XeFX4\ce{XeF4} is nonpolar.

See alsoOctahedralSquare pyramidalPolar molecule