Arsenic Pentachloride Polar Or Nonpolar

Arsenic pentachloride (AsCl5) is a polar molecule.

To understand why, we need to look at the molecular geometry and the polarity of its bonds. In AsCl5, there are five chlorine atoms bonded to an arsenic atom, forming a trigonal bipyramidal molecular shape. The three chlorine atoms in the equatorial positions are arranged symmetrically around the central arsenic atom, while the two chlorine atoms in the axial positions are positioned above and below the plane of the equatorial chlorine atoms.

The polarity of each As-Cl bond depends on the difference in electronegativity between the two atoms. Electronegativity is a measure of an atom's ability to attract electrons towards itself in a chemical bond. In AsCl5, the electronegativity of chlorine (3.16) is higher than that of arsenic (2.18), indicating a polar covalent bond between them. This means that each As-Cl bond has a dipole moment, with the chlorine atom carrying a partial negative charge and the arsenic atom carrying a partial positive charge.

When we consider the molecular geometry and the polarities of the individual bonds, we find that the dipole moments do not cancel out due to the asymmetrical arrangement of the bonds. As a result, the overall molecular dipole moment of AsCl5 is nonzero, making it a polar molecule.