Question

Which of the following have linear structure?
I. $SnCl _{2}$
II. $BeF _{2}$
III. $SO _{2}$
IV. $ \overset{+}{N}O _{2}$
V. $C _{2} H _{2}$

• A. I, II, IV
• B. II, IV, V
• C. II, III, IV
• D. I, V , V

Answer 1

Answer: (B)

Structure of :

I.$ SnCl _{2} \,Sn$ have $4 $ valence electrons, which form two sigma ( $\sigma$ ) bonds and have one lone pair $(l p)$ of electrons over $Sn$ atom, thus have $V$-shaped structure.

II. $B e F _{2} F - Be - F$
Linear Be have two valence electrons bonded with $2 F$ -atoms, thus has no $l p$ of electrons and have linear structure.


III. $SO _{2}$ Sulphur $( S )$ have six $(6)$ valence electrons, out of which sulphur can form one coordinate sigma, one simple $(\sigma)$ and one $pi\, (\pi)$ bond with $O$-atoms having one $lp$ of electrons over sulphur atom. Thus, $SO _{2}$ have bent structure.

IV. $ \overset{+}{N} O _{2}$ Nitrogen in $NO _{2}$ have four $(4)$ electrons in its outermost shell, which are involved in formation of


one coordinate, one simple sigma and one $\pi$ - bond with $O$-atoms. It has no $lp$ of electrons over $N$-atom, thus have linear structure.

V . $C _{ 2 } H _{2} \underset{\text{(Linear)}}{H - C \equiv C - H}$

Carbon has four valence electrons which forms two sigma bonds with two $H$ -atoms one by each $C$ -atom) and one sigma bond between two $C$-atoms. It also forms two $pi \,(\pi)$ bonds between two $C$-atoms to complete its octate. Thus, has linear structure.