The P-Cl bond is classified as a polar covalent bond. Let’s break down why this is the case.
Firstly, the bond in question is formed between phosphorus (P) and chlorine (Cl). These two elements are different and have differing electronegativities. Electronegativity is a measure of an atom’s ability to attract and hold onto electrons. Chlorine is more electronegative than phosphorus, meaning it has a stronger tendency to attract electrons.
When phosphorus and chlorine bond, the electrons that are shared between the two atoms will spend more time closer to the chlorine atom due to its higher electronegativity. This unequal sharing of electrons creates a dipole moment, where one end of the molecule becomes slightly negatively charged (the end with chlorine) and the other end becomes slightly positively charged (the phosphorus end).
This characteristic of having partial positive and partial negative charges is what makes the P-Cl bond a polar covalent bond. In contrast, if the bond were ionic, one atom would completely transfer its electron(s) to the other, resulting in a charge separation without the idea of sharing. If it were nonpolar covalent, the atoms would share electrons equally, which is not the case here.
In summary, the P-Cl bond is polar covalent because of the difference in electronegativity between phosphorus and chlorine, resulting in an unequal sharing of electrons.