Question

Which molecule is not linear?

• A. $ CO_{2} $
• B. $ SO_{3} $
• C. $ C_{2}H_{2} $
• D. $ MgCl_{2} $

Answer 1

Answer: (B)

Hybridisation and shape of molecule is decided by following formula.
$ H=\frac{1}{2}(V+X-C+A) $
where H = hybridisation
$V =$ number of electrons in valance shall of central atom
$X =$ number of monovalent atoms
$C =$ charge on cation
$A = $ charge on anion
$ CO_{2} $
$ H=\frac{1}{2}(4+0-0+0) = 2 $
$ \therefore sp$ hybridisation so shape is linear.
$ S{{O}_{2}} H=\frac{1}{2}(6+0-0+0) = 3 $
$\therefore sp^{2} $ hybridisation so shape is trigonal planar.
$ C_{2}H_{2}$ Each carbon is sp hybridised and linear in shape.
$ MgC{{l}_{2}} H=\frac{1}{2}(2+2-0+0) $
$ \therefore sp$ hybridisation and linear is the shape.