Which of the following molecular species is not linear?

(1) $(\mathrm{CN}{)}_2$                                                       

(2) ${\mathrm{OCN}}^{-}$

(3) ${\mathrm{XeF}}_2$                                                         

(4) ${\mathrm{S}}_3^{2-}$

Which of the following statement is correct about ${I_3}^{+}$and ${I_3}^{-}$ molecure ions?

  (1) Number of lone pairs at central atoms are samein both molecure ions

  (2) Hybridization of central atoms in both ions are same

  (3) both are polar spacies

  (4) both are planar spacies

The compound that has the highest ionic character associated with the X-Cl bond is:

1. ${\mathrm{PCl}}_5$ 

2. ${\mathrm{BCl}}_3$

3. ${\mathrm{CCl}}_4$

4. ${\mathrm{SiCl}}_4$

In which of the folllowing transformations, the bond order has increased and the magnetic behaviour has changed?

(a) ${\mathrm{C}}_2^{+}\to {\mathrm{C}}_2$                      (b) ${\mathrm{NO}}^{+}\to \mathrm{NO}$

(c) ${\mathrm{O}}_2\to {\mathrm{O}}_2^{+}$                       (d) ${\mathrm{N}}_2\to {\mathrm{N}}_2^{+}$

The bond having the highest bond energy is :

(1) C=C 

(2) C=S

(3) C=O

(4) P=N

H.O.M.O. (Highest Occupied Molecular Orbital) of CO molecular is :

(1) Non-bonding M.O. with slight antibonding character

(2) Non-bonding M.O. with slight bonding character

(3) Pure non-bonding M.O.

(4) None of the above

An incorrect match among the following is:

In which of the following species central atom is NOT surrounded by exactly 8 valence electrons?

(1) $B{F_4}^{-}$

(2) $NC{l}_3$

(3) $PC{l_4}^{+}$

(4) $S{F}_4$

The structure of ${\mathrm{B}}_3{\mathrm{N}}_3{\mathrm{H}}_6$ is as follows :

How many derivative structures of ${\mathrm{B}}_3{\mathrm{N}}_3{\mathrm{H}}_4{\mathrm{X}}_2$ can be derived from the basic structure, by the

replacement of two hydrogen atoms?

(a) 2                                         (b) 3

(c) 4                                         (d) 5    

Correctly match is :

(1) ${\mathrm{d}}_{{\mathrm{x}}^2-{\mathrm{y}}^2}$ atomic orbital                                    $—$One nodal plane 

(2) $P_y$ atomic orbital                                          $—$Two nodal plane 

(3) ${\sigma }_{px}$                                                              $—\psi$ (gerade)

(4) ${\pi }_{py}$                                                              $—\psi$ (ungerade)