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)

In which of the following molecular shape $d_{z^{2-}}$ orbital must not be involved in bonding?

(1) Pentagonal planar 

(2) Trigonal planar 

(3) Linear 

(4) Square planar

Consider the following reaction:

${\mathrm{MX}}_4+\mathrm{X}{\text{'}}_2\to {\mathrm{MX}}_4\mathrm{X}{\text{'}}_2$

If atomic number of M is 52 and X and X' are halogens and X' is more electronegative than X.

Then choose correct statement regarding given information:

(a) Both X' atoms occupy axial positions which are formed by overlapping of p and d-orbitals only

(b) All $\mathrm{M}—\mathrm{X} \mathrm{bond} \mathrm{lengths} \mathrm{are} \mathrm{identical} \mathrm{in} \mathrm{both} {\mathrm{MX}}_4 \mathrm{and} {\mathrm{MX}}_4\mathrm{X}{\text{'}}_2 \mathrm{compounds}$

(c) Central atom 'M' does not use anyone valence non-axial set of d-orbital in hybridization of final product

(d) Hybridization of central atom 'M' remains same in both reactant and final product.