Question

Give reason for the following:
$PbC{{l}_{4}}$ is more covalent than $PbC{{l}_{2}}$.

Answer 1

Hint: Covalent bond is the bond formed between hydrogen and chlorine that is formed between these two species because of their varying electronegativities which tends them to become polarized. This happens because the more electronegative atom which is chlorine in this case pulls the bond pair of electrons closer to itself by developing a partially negative charge on it and positive charge on hydrogen.

Complete answer:
The strength of a covalent bond is highly dependent on the electronegativities of the two bonded atoms or we can say that the difference between the electronegativities of the bonded atoms. A nonpolar covalent bond is defined as a type of chemical bond which is formed when electrons are shared equally between two atoms. Thus in an atom the number of electrons shared by the adjacent atoms will be the same. Whereas electronegativity represents the net result of the tendencies of atoms in different elements to attract the bond-forming electron pairs.
$PbC{{l}_{4}}$ is more covalent than $PbC{{l}_{2}}$, Because $Pb$ known by the name lead is in +4 oxidation state in case of $PbC{{l}_{4}}$ and has high charge/size ratio as compare to $P{{b}^{2+}}$ thus the polarizing power of $P{{b}^{4+}}$ is greater as compare to $P{{b}^{2+}}$. Hence we can say that $PbC{{l}_{4}}$ is more covalent.

Note:
The covalent bond is also termed as nonpolar because the difference in electronegativity is mostly negligible. This type of bond is also formed when atoms that share a polar bond arrange themselves in such a manner that electric charges between them tend to cancel each other