Chemical Bonding and Molecular Structure

The difference in boiling or melting point, even after nearly the same molecular geometry, is because opf the presence of hydrogen bond. HF forms intermolecular hydrogen bonds due to fluorine's high electronegativity. This intermolecular hydrogen bonding requires more energy due to break the hydrogen bonds and melt or boil. So, stronger intermolecular forces of HF result in a higher boiling point.

Xenon has 8 valence electrons. In ${\mathrm{X}\mathrm{e}\mathrm{F}}_2$ , it forms two bonds with fluorine, leaving three lone pairs. The steric number =2 bonds +3 lone pairs $=5$ .
As per the VSEPR Theory  the electron? pair geometry due to SN = 5 will be trigonal bipyramidal. The hybridization type will be ${\mathrm{s}\mathrm{p}}^3\mathrm{d}$ hybridisation. However, the three lone pairs occupy equatorial positions, resulting in a linear molecular geometry.

SO₃ -> Sp² Planar

BF₃ -> Sp² Planar

$N{O}_3^{-}$ -> Sp² Planar

SF₄ -> Sp³d non-planar

H₂O₂ -> Sp³ Non-planar

PCl₃ -> Sp³ Non –planar

[Al (OH)₄]^{- ->} Sp³ Non-planar

XeF₄ -> Sp³d² planar

XeO₃ -> Sp³ Non-planar

$P{H}_4^{-}$ -> Sp³ Non-planar

Molecules usually form chemical bond through either sharing or through rtransfering the electrons. During covalent bonding the electron pairs shared between atoms to form covalent bond are called shared pair or bond pair. At the same time, the electron pair which is not involved in sharing is called lone pair of electrons.

For example: CH₄ has 4 bond pairs but H₂O has 2 bond pairs and 2 lone pairs.

$B_2={\sigma }_{1s}^2{\sigma }_{1s}^{*2}{\sigma }_{2s}^2{\sigma }_{2s}^{*2}{\pi }_{2px}^1={\pi }_{2py}^1\to$ Paramagnetic

$\begin{array}{l}L{i}_2={\sigma }_{1s}^2{\sigma }_{1s}^{*2}{\sigma }_{2s}^2\to Diamagnetic\\ C_2={\sigma }_{1s}^2{\sigma }_{1s}^{*2}{\sigma }_{2s}^2{\sigma }_{2s}^{*2}{\pi }_{2px}^2\equiv {\pi }_{2py}^2\to Diamagnetic\\ C_2^{-}={\sigma }_{1s}^2{\sigma }_{1s}^{*2}{\sigma }_{2s}^2{\sigma }_{2s}^{*2}{\pi }_{2px}^2\equiv {\pi }_{2py}^2{\sigma }_{2pz}^1\to Paramagnetic\end{array}$

$O_2^{-2}={\sigma }_{1s}^2{\sigma }_{1s}^{*2}{\sigma }_{2s}^2{\sigma }_{2s}^{*2}{\sigma }_{2pz}^2{\pi }_{2px}^2\equiv {\pi }_{2py}^2{\pi }_{2px}^{*2}\equiv {\pi }_{2py}^{*2}$ Diamagnetic

$O_2^{+}={\sigma }_{1s}^2{\sigma }_{1s}^{*2}{\sigma }_{2s}^2{\sigma }_{2s}^{*2}{\sigma }_{2pz}^2{\pi }_{2px}^2\equiv {\pi }_{2py}^2{\pi }_{2px}^{*1}\equiv {\pi }_{2py}^0\to$  Paramagnetic

$H{e}_2^{+}={\sigma }_{1s}^2{\sigma }_{1s}^{*1}\to$ Paramagnetic

$\therefore$ Paramagnetic molecules are ${}_{}{}_{}^{}{}_{}^{}{}_{}^{}$ $=B_2,C_2^{-},O_2^{+},H{e}_2^{+}$

The name of covalent and ionic bonds tell their formation story in small detail. Co- means sharing or coexisting, so whenever there is bond fromation due to sharing of valence electron,  it is known as covalent bond. Similerly, ionic bonds suggest that when a bond formation takes place due to ions, which attract each other, it is considered as ionic bond. Ionic bonds are also known as electrovalent bonds. There are some major differences between Electrovalent and covalent bonds. Chekc the table below:

For more detail related to the chemical bonding in class 11 chemistry read our notes.

Chemical Bonding and Molecular Structure

In sulphide ore, depressants selectively prevent impurity from coming to the fourth.