Phosphorous trichloride is a polar molecule because the electronegativity of the chlorine atoms is greater than that of the phosphorous atom.
Question:
VSEPR is the acronym representing valence shell electron pair repulsion. Its a theory that utilizes the electron geometry of a molecule to predict its molecular geometry. Based on the molecular geometry, we can determine if the molecule is polar or nonpolar.
Preparation and reaction of PCl3
Phosphorus trichloride(PCl3) is a bright yellowish liquid with a strong intense odor. It is created primarily through the chlorination of phosphorus. It is the heterogeneous reaction, phosphorus in the soft solid phase and chlorine in the gas phase. Initially, phosphorus reacted with chlorine gas formed phosphorus trichloride(PCl3).
It is an exothermic reaction. The chemical equation of phosphorus chlorination exothermic reaction is shown below.
Reaction of PCl3:
Why is PCl3 a polar molecule?
Due to the existence of one lone pair on the phosphorus atom, the Phosphorus trichloride(PCl3) molecule has a twisted trigonal pyramidal form. According to the VSEPR hypothesis, lone pairs and bond pairs repel each other, causing the P-Cl bonds to move the lower side of the tetrahedral molecular structure, resulting in a trigonal pyramidal molecule.
The dipole moment of P-Cl bonds does not cancel out as it does in asymmetric PCl3 molecules. PCl3 has a dipole moment of 0.97D across the entire molecule. The formation of a polar molecule is caused by the geometrical structure and the difference in electronegativity value of atoms in the PCl3 molecule.
Because of the asymmetric tetrahedral shape of the PCl3 molecule, the charge is dispersed non-uniformly among the phosphorus and three chlorine atoms, resulting in the formation of positive and negative poles across the PCl3 molecule.
FAQ
Why is PCl3 polar?
Is PCl3 ionic or polar?
What kind of bond does PCl3 have?
