What is the molecular geometry of XeCl_4 according to its Lewis structure?

• A. Tetrahedral
• B. Trigonal bipyramidal
• C. Square planar
• D. Octahedral

Answer: (C)

Verified step by step guidance

1. Step 1: Draw the Lewis structure of XeCl_4. Xenon (Xe) is the central atom with 8 valence electrons, and each chlorine (Cl) atom contributes 7 valence electrons. Total valence electrons = 8 (Xe) + 4 × 7 (Cl) = 36 electrons.
2. Step 2: Arrange the four chlorine atoms around the xenon atom and form single bonds between Xe and each Cl. Each bond uses 2 electrons, so 4 bonds use 8 electrons, leaving 28 electrons to be placed as lone pairs.
3. Step 3: Complete the octets of the chlorine atoms by placing 6 electrons (3 lone pairs) on each Cl atom. This uses 24 electrons (4 × 6), leaving 4 electrons to be placed on the xenon atom as lone pairs.
4. Step 4: Place the remaining 4 electrons as 2 lone pairs on the xenon atom. Now, xenon has 4 bonding pairs and 2 lone pairs.
5. Step 5: Use the VSEPR theory to determine the molecular geometry. With 6 electron pairs (4 bonding + 2 lone pairs), the electron geometry is octahedral, but the molecular shape (ignoring lone pairs) is square planar.