Chemistry Chemical Bonding and Molecular Structure

Following have the sp³d² hybridisation

$B_2={\sigma }_{1s}^2{\sigma }_{1s}^{*2}{\sigma }_{2s}^2{\sigma }_{2s}^{*2}{\pi }_{2px}^1={\pi }_{2py}^1\to$ 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 ${}_{}{}_{}^{}{}_{}^{}{}_{}^{}$ $=B_2,C_2^{-},O_2^{+},H{e}_2^{+}$

Number of electrons in

$P{H}_3=15+3=18$

$B_2{H}_6=5*2+6=16$

$\begin{array}{l}CC{l}_4=6+17*4=6+68=74\\ N{H}_3=7+1*3=10\\ LiH=3+1=4\\ BC{l}_3=5+17*3=56\end{array}$

$B_2{H}_6\&BC{l}_3$ are e^- deficient molecules. B₂H₆ is dimer of BH₃, both compound has 6e^- only.

Bond strength $\propto$ Bond order

$N_2\to {\sigma }_{1s}^2{\sigma }_{1s}^{*2}{\sigma }_{2s}^2{\sigma }_{2s}^{*2}{\pi }_{2px}^2\equiv {\pi }_{2py}^2{\sigma }_{2pz}^2$

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

$C_2\to {\sigma }_{1s}^2{\sigma }_{1s}^{*2}{\sigma }_{2s}^2{\sigma }_{2s}^{*2}{\pi }_{2px}^2\equiv {\pi }_{2py}^2$

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

NO Number of electron = 7 + 8 = 15

B.O. Similar to $N_2^{-}$

$N_2^{-}\to {\sigma }_{1s}^2{\sigma }_{1s}^{*2}{\sigma }_{2s}^2{\sigma }_{2s}^{*2}{\pi }_{2px}^2\equiv {\pi }_{2py}^2{\sigma }_{2pz}^2{\pi }_{2px}^{*1}\equiv {\pi }_{2py}^{*}$

B.O. of N₂ = 3B.O of C₂ = $\frac{8-4}{2}=2$

Removal of e form antibonding molecular orbital increases bond order.

In NO & O₂ has valance e in orbital.

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

Bond order of   $C_2^{2-}=\frac{N_B-N_A}{2}=\frac{10-4}{2}=3$

Bond order of $N_2^{2-}=\frac{N_B-N_A}{2}=\frac{10-6}{2}=2$

Bond order of   $O_2^{2-}=\frac{N_B-N_A}{2}=\frac{10-8}{2}=1$

N_B = No. of electrons in bonding molecular orbitals.

N_A = No. of electron is Anti bonding molecular orbitals

${\left[PtC{l}_4\right]}^{2-}\to Pt$ has dsp² hybridization

BrF₅ -> Br has sp³d² hybridization

PCl₅ -> P has sp³d hybridization

[Co (NH₃)₆]³⁺ -> Co has d²sp³ hybridization.

Moles of PCl₅ = 5 mol

Moles of Ar = 4 mol

Total no of moles = 9 moles

^{$P_{Total}=\frac{nRT}{V}=\frac{9*0.0821*610}{100}=4.5atm$}

^{$P_{PC{l}_5}=X_{PC{l}_5}*P_T=\frac{5}{9}*4.5=2.5atm$}

^{$P_{Ar}=X_{Ar}*P_T=\frac{4}{9}*4.5=2atm$}

$PC{l}_5\stackrel{}{?}PC{l}_3+C{l}_2$

2.5 00

2.5 PPP

$P_{Total}=2.5-P+P+P+P_{Ar}=6$

P = 1.5 atm

$K_P=\frac{1.5*1.5}{1}=2.25$