Question

Deduce the geometry of each of the following molecules.

(i) $N{H}_3$
(ii) $C_2{H}_4$
(iii) ${Cl{O}_3}^{-}$

• A. (i) pyramidal, (ii) pyramidal, (iii) tetrahedral
• B. (i) pyramidal, (ii) tetradedral, (iii) pyramidal
• C. (i) pyramidal, (ii) planar, (iii) tetrahedral
• D. (i) pyramidal, (ii) planar, (iii) pyramidal

Answer 1

The correct option is D (i) pyramidal, (ii) planar, (iii) pyramidal

$H=\frac{1}{2}[V+M-C+A]$
where,
H= Number of orbitals involved in hybridization
V=Valence electrons of central atom
M- Number of monovalent atoms linked to central atom
C= Charge of cation
A= Charge of anion
Consider the hybridization and shape of the options:-
A) $N{H}_3$
$H=\frac{1}{2}[5+3]=4$ $\Rightarrow s{p}^3$ hybridized state with 1 lone pair
It is pyramidal in shape.
B) $C_2{H}_4$\ It is an alkene. Since it possess a double bond, it has to be planar in shape.
C) $Cl{O}_3^{-}$
$H=\frac{1}{2}[7+1]=4$ $\Rightarrow s{p}^3$ hybridized state with 1 lone pair
It is pyramidal in shape.