Determining the Molecular Shape of XeO₂F₂

Step 1: Calculate the total number of valence electrons

Xenon (Xe) has 8 valence electrons, each oxygen (O) contributes 6, and each fluorine (F) contributes 7:

$Total = 8 + 2 \times 6 + 2 \times 7 = 8 + 12 + 14 = 34$

Step 2: Determine the electron geometry using VSEPR theory

Xenon is the central atom with 4 atoms attached (2 O and 2 F) and 1 lone pair (from 34 electrons: 8 bonds use 16 electrons, leaving 18 for 9 pairs; 4 bonding pairs and 5 lone pairs total, but xenon shares only 4 pairs in bonds, so it has 1 lone pair).

Steric number = number of atoms bonded + number of lone pairs = 4 + 1 = 5

This corresponds to trigonal bipyramidal electron geometry.

Step 3: Determine the molecular shape

With 4 bonding pairs and 1 lone pair in a trigonal bipyramidal arrangement, the lone pair occupies an equatorial position to minimize repulsion. The molecular shape is see-saw (or distorted tetrahedral).

Final Answer: see-saw

Related Topics

VSEPR Theory (Valence Shell Electron Pair Repulsion)
Molecular Geometry Predictions
Hybridization in Molecules
Lone Pair-Bond Pair Repulsions

Key Formulae and Theory

Steric Number (SN) = Number of atoms bonded to central atom + Number of lone pairs on central atom

Common geometries:

SN=2: Linear
SN=3: Trigonal Planar
SN=4: Tetrahedral
SN=5: Trigonal Bipyramidal
SN=6: Octahedral

Lone pairs occupy equatorial positions in trigonal bipyramidal geometry to minimize electron repulsion, leading to see-saw shape when one lone pair is present.