Question

The correct geometry and hybridization for ${XeF_4}$ are

• A. octahedral, $sp^3d^2$
• B. trigonal bipyramidal, $sp^3d$
• C. planar triangle, $sp^3d^3$
• D. square planar, $sp^3d^2$

Answer 1

The Correct Option is D

The question asks for the correct geometry and hybridization of ${XeF_4}$. To determine this, we need to analyze the molecular structure and the type of hybrid orbitals involved.

1. Firstly, calculate the total number of valence electrons:
   Xenon (Xe) has 8 valence electrons, and each Fluorine (F) atom has 7 valence electrons. For ${XeF_4}$, there are four F atoms, contributing a total of 4 x 7 = 28 electrons.
   Total = 8 (from Xe) + 28 (from 4 F) = 36 valence electrons.
2. Distribute the valence electrons:
   Place one electron pair between Xe and each F to form a bond, using 8 electrons (2 electrons per bond * 4 bonds = 8 electrons).
   Remaining = 36 - 8 = 28 electrons.
3. With the remaining 28 electrons, place lone pairs on the fluorine atoms (each needs 6 more electrons to complete their octet). This uses up 24 electrons (4 F atoms x 6 electrons each).
4. The remaining 4 electrons form 2 lone pairs on Xe.
5. Determine hybridization:
   The steric number for Xe, which is the number of bonds (4 Xe-F sigma bonds) plus the number of lone pairs (2 lone pairs), is 6.
   A steric number of 6 means the hybridization is ${sp^3d^2}$.
6. Determine molecular geometry:
   With 4 bonding pairs and 2 lone pairs, the geometry is "octahedral" for the electron pairs, but the shape determined by the positions of the atoms (ignoring lone pairs) is square planar.

Thus, the correct geometry is square planar, and the hybridization is ${sp^3d^2}$.

Therefore, the correct answer is "square planar, ${sp^3d^2}$". This eliminates other options:

• Option 1: While it suggests the same hybridization ${sp^3d^2}$, the geometry is incorrect as octahedral is the electron pair arrangement, not the molecular geometry.
• Option 2: Trigonal bipyramidal ${sp^3d}$ hybridization is incorrect for this molecule.
• Option 3: Planar triangle ${sp^3d^3}$ hybridization is incorrect both in terms of geometry and hybridization.