ICl3 and ICl5
Steric Number on central atom
Hybridization in Central atom
Electron geometry on central atom
Molecular geometry
Symmetrical or not
Bonds polar or nonpolar
Sym bond dipoles polar or nonpolar
The Correct Answer and Explanation is :
Let’s analyze the two compounds: ICl₃ (Iodine trichloride) and ICl₅ (Iodine pentachloride).
1. ICl₃ (Iodine trichloride):
- Steric Number on the Central Atom: The central atom is iodine (I), which is bonded to three chlorine atoms. Additionally, iodine has two lone pairs of electrons. Therefore, the steric number is 5 (3 bonding pairs + 2 lone pairs).
- Hybridization: With a steric number of 5, the hybridization of iodine is sp³d. This involves one s orbital, three p orbitals, and one d orbital.
- Electron Geometry: The electron geometry around iodine in ICl₃ is trigonal bipyramidal due to the presence of 5 electron regions (3 bonds + 2 lone pairs).
- Molecular Geometry: The molecular geometry in ICl₃ is T-shaped because the lone pairs occupy equatorial positions to minimize repulsion, leaving the 3 bonds in a T-shape.
- Symmetrical or Not: ICl₃ is not symmetrical. The T-shaped arrangement of atoms creates a molecular geometry that results in an overall dipole moment.
- Bonds (Polar or Nonpolar): The I-Cl bond is polar due to the difference in electronegativity between iodine and chlorine.
- Bond Dipoles (Polar or Nonpolar): Because of the T-shaped molecular geometry and polar bonds, the bond dipoles do not cancel out, making the overall molecular dipole polar.
2. ICl₅ (Iodine pentachloride):
- Steric Number on the Central Atom: The central atom is iodine, which is bonded to five chlorine atoms. Iodine also has one lone pair of electrons, making the steric number 6 (5 bonding pairs + 1 lone pair).
- Hybridization: With a steric number of 6, the hybridization of iodine is sp³d² (one s orbital, three p orbitals, and two d orbitals).
- Electron Geometry: The electron geometry of ICl₅ is octahedral due to 6 electron regions (5 bonds + 1 lone pair).
- Molecular Geometry: The molecular geometry is square pyramidal because the lone pair occupies one of the axial positions, leaving the 5 bonds arranged in a square pyramid.
- Symmetrical or Not: ICl₅ is not symmetrical. The square pyramidal shape leads to an overall dipole moment.
- Bonds (Polar or Nonpolar): The I-Cl bonds are polar due to the electronegativity difference between iodine and chlorine.
- Bond Dipoles (Polar or Nonpolar): As the molecular geometry is not symmetrical, the bond dipoles do not cancel out, making the overall molecular dipole polar.
Summary:
- ICl₃ has a T-shaped geometry, is polar with polar bonds and bond dipoles.
- ICl₅ has a square pyramidal geometry, is also polar with polar bonds and bond dipoles. Both compounds have non-symmetrical shapes that lead to a net molecular dipole moment.