Question

In which of the following species maximum atom can lie in the same plane?

• A. XeF$_{2}$O$_{2}$
• B. PCl$_{5}$
• C. AsH$_{4}^{+}$
• D. XeF$_{4}$

Answer 1

Answer: (D)

XeF$_{4}$

Answer 2

To determine the maximum number of atoms that can lie in the same plane for each species, we first need to determine their molecular geometries using VSEPR theory.

1. Determine the molecular geometry for each species:

• A) XeF$_{2}$O$_{2}$

  Molecular geometry: See-saw. In a see-saw structure, the central atom (Xe), the two axial atoms (F), and one of the equatorial atoms (O) can lie in the same plane. This gives 4 atoms (F, Xe, F, O). Alternatively, Xe, the two equatorial O atoms, and one axial F atom can be coplanar, also giving 4 atoms.

• B) PCl$_{5}$

  Molecular geometry: Trigonal bipyramidal. In a TBP structure, the central atom (P) and the three equatorial atoms (Cl) lie in the same plane. This gives 4 atoms (P, Cl, Cl, Cl).

• C) AsH$_{4}^{+}$

  Molecular geometry: Tetrahedral. In a tetrahedral structure, a maximum of 3 atoms can lie in the same plane (e.g., the central As atom and two H atoms, or any three H atoms).

• D) XeF$_{4}$

  Molecular geometry: Square planar. In a square planar structure, the central atom (Xe) and all four terminal atoms (F) lie in the same plane. This gives 5 atoms (Xe, F, F, F, F).

2. Compare the maximum number of atoms in a plane for each species:

• XeF$_{2}$O$_{2}$: 4 atoms
• PCl$_{5}$: 4 atoms
• AsH$_{4}^{+}$: 3 atoms
• XeF$_{4}$: 5 atoms

The maximum number of atoms that can lie in the same plane is 5, which occurs in XeF$_{4}$.