- Exam
- JEE Main
- Year
- 2022
- Date
- 27 June
- Shift
- Evening Shift
- Subject
- Chemistry
- Chapter
- Chemical Bonding and Molecular Structure
JEE Main 2022 · 27 June · Evening Shift · Chemistry · Chemical Bonding and Molecular Structure
Identify the incorrect statement for PCl _ 5 from the following.
Options
- AIn this molecule, orbitals of phosphorous are assumed to undergo hybridization.
- BThe geometry of is trigonal bipyramidal.
- C has two axial bonds stronger than three equatorial bonds.
- DThe three equatorial bonds of lie in a plane.
Correct answer
C. has two axial bonds stronger than three equatorial bonds.
Step-by-step solution
sp3d hybridization is shown in phosphorus penta chloride (PCl5). The grounds state and the excited state outer electronic configurations of phosphorus (Z=15) are represented below
Now the five orbitals (i.e., one s, three p and one d orbitals) are available for hybridization to yield a set of five sp3d hybrid orbitals which are directed towards the five corners of a trigonal bipyramidal as depicted in the below.
It should be noted that tall the bond angles in trigonal bipyramidal geometry are not equivalent. In PCl5 the five sp3d orbitals of phosphorus overlap with the singly occupied p orbitals of chlorine atoms to form five P-Cl sigma bonds. Three P-Cl bond lie in one plane and make an angle of 120o with each other; these bonds are termed as equatorial bonds. The remaining two P-Cl bonds-one lying above and the other lying below the equatorial plane, make an angle of 90o with the plane. These bonds are called axial bonds. As the axial bond pairs suffer more repulsive interaction form the equatorial bond pairs, therefore axial bonds have been found to be slightly longer and hence slightly weaker than the equatorial bonds; which makes PCl5 molecule more reactive.