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

(a) $B{F_4}^{-}$

(b) $NC{l}_3$

(c) PC${l_4}^{+}$

(d) $S{F}_4$

Which bond is expected to be the least polar?

(1) O-F

(2) P-F

(3) Si-N

(4) B-F 

Which set contains only covalently bonded molecules?

(a) $BC{l}_{3 }, SiC{l}_4 ,PC{l}_3$

(b) $N{H}_{4}Br , N_2{H}_4,HBr$

(c) $I_{2 ,}{H}_{2}S , NaI$

(d) $A{l}_2,O_{3 }, A{S}_4$

Which of the following statement is true for $I{O}_2{F_2}^{-}$according to VSEPR theory?

(A) The lone pair and two I-O double bonds occupy the equatorial positions of trigonal
bipyramidal.

(B) It has $s{p}^3$ hybridization and is T-shaped.

(C)  Its structure is analogous to $S{F}_4$.

(D) (A) and (C) both

Which of the following is most covalent?

1. \(AlF_3\)

2. \(AlCl_3\)

3. \(AlBr_3\)

4. \(AlI_3\)

Among LiCl, BeCl₂, BCl₃ and CCl₄, the covalent bond character follows the order-

1. LiCl < BeCl₂ > BCl₃ > CCl₄

2. LiCl > BeCl₂ < BCl₃ < CCl₄

3. LiCl < BeCl₂ < BCl₃ < CCl₄

4. LiCl > BeCl₂ > BCl₃ > CCl₄

The dipole moment of toluene is 0.36 D. The dipole moment of o-xylene would be

1.  0.0 D

2.  0.36 D

3.  0.62 D

4.  0.92 D

A molecule among the following with non-zero dipole moment is:

1. ${\mathrm{C}}_6{\mathrm{Cl}}_6$

2. ${\mathrm{C}}_2{\mathrm{Cl}}_6$

3. $\mathrm{C}{\left({\mathrm{CCl}}_3\right)}_4$

4. $:{\mathrm{CCl}}_2$

Both ${\mathrm{CN}}^{-} \mathrm{and} {\mathrm{N}}^2$ isoelectronic but in contrast to ${\mathrm{CN}}^{-} , {\mathrm{N}}^2$ is chemically inert due to

1.  Unsymmetrical electron distribution

2.  Low bond energy

3.  The pressure of a greater number of electrons in bonding orbitals

4.  Absence of bond polarity