Question

Identify the incorrect statement for \(PCl_5\) from the following.

• A. In this molecule, orbitals of phosphorous are assumed to undergo \(sp^3d\) hybridization
• B. The geometry of \(PCl_5 \)is trigonal bipyramidal.
• C. \(PCl_5\) has two axial bonds stronger than three equatorial bonds.
• D. The three equatorial bonds of \(PCl_5\) lie in a plane

Answer 1

The Correct Option is C

To determine the incorrect statement about \(PCl_5\), we need to analyze each given option based on the chemical and structural properties of phosphorus pentachloride.

1. \(sp^3d\) Hybridization of Phosphorus in \(PCl_5\):
   The phosphorus atom in \(PCl_5\) uses \(sp^3d\) hybridization. This involves mixing one s orbital, three p orbitals, and one d orbital to form five equivalent hybrid orbitals. These orbitals form the bonds with the chlorine atoms. Therefore, this statement is correct.
2. Trigonal Bipyramidal Geometry:
   The geometry of \(PCl_5\) is indeed trigonal bipyramidal, which consists of two axial positions and three equatorial positions surrounding the phosphorus atom. Thus, this statement is also correct.
3. Axial and Equatorial Bonds:**
   In a trigonal bipyramidal structure, the three equatorial bonds lie at 120° to each other in one plane, while the two axial bonds are aligned perpendicularly to this plane. The axial bonds are actually longer and therefore weaker due to greater repulsion compared to equatorial bonds.
   This statement: "**\(PCl_5\) has two axial bonds stronger than three equatorial bonds**" is incorrect. The axial bonds are generally longer and weaker because of the increased bond angle strain and repulsion from the equatorial bonds.
4. Equatorial Bonds in a Plane:
   The three equatorial bonds of \(PCl_5\) do indeed lie in the same plane, making this statement correct.

Therefore, the incorrect statement is: "\(PCl_5\) has two axial bonds stronger than three equatorial bonds."