Which reaction involves a change in the electron-pair geometry for the underlined atom?

1. BF₃ $+{\mathrm{F}}^{-}\to {\mathrm{BF}}_4^{-}$ 

2. NH₃$+{\mathrm{H}}^{+}\to {\mathrm{NH}}_4^{+}$

3. 2SO₂$+{\mathrm{O}}_2\to 2{\mathrm{SO}}_3$ 

4. H₂O$+{\mathrm{H}}^{+}\to {\mathrm{H}}_3{\mathrm{O}}^{+}$   

The correct order of increasing s-character (in percentage) in the hybrid orbitals of following molecules/ion is :

(i) ${\mathrm{CO}}_3^{2-}$   (ii) XeF₄     (iii) ${\mathrm{I}}_3^{-}$       (iv) NCl₃   (v) BeCl₂

1.  ii < iii < iv < i < v

2. ii < iv < iii < v < i

3. iii < ii < i < v < iv        

4. ii < iv < iii < i < v

Which of the following condition show linear geometry (b.p. = Bond pair, I.p. = Lone pair) :

(a)  Molecule in which central atom show sp³d hybridisation and contain 3 b.p. and 2 l.p.

(b)  Any diatomic molecule

(c)  Tri-atomic molecule in which central atom has 2 l.p and 2$\mathrm{\sigma }$ b.p.

(d)  Molecule in which central atom has 2$\mathrm{\sigma }$ b.p. and 2$\mathrm{\pi }$ b.p. and contain no. l.p.

1. a, b                       2. b, d

3. a, c, d                   4. a, b, c, d

Which is non-angular species :

1. ${\mathrm{I}}_3^{+}$                2. ${\mathrm{ClO}}_2^{-}$    

3. SO₂              4. ${\mathrm{I}}_3^{-}$  

Match the column :

1. P = II, Q = IV, R = III, S = VI

2.  P = II, Q = IV, R = I, S = V

3.  P = II, Q = I, R = V, S = VI  

4.  P = II, Q = I, R = III, S = IV

The molecule/s that will have non zero dipole moments is /are : 

1. 1,2-dichloro benzene.
2. Cis-3-hexene.
3. Trans-2-pentene.
4. All of the above.

Among the following species, identify the isostructural pairs :

NF₃, , BF₃, H₃O⁺, HN₃, ${\mathrm{NO}}_3^{-}$

1. [NF₃,${\mathrm{NO}}_3^{-}$ ] and [BF₃, H₃O⁺]                  

2. [NF₃, HN₃] and [${\mathrm{NO}}_3^{-}$, BF₃]   

3. [NF₃, H₃O⁺] and [${\mathrm{NO}}_3^{-}$, BF₃]         

4. [NF₃, H₃O⁺] and [HN₃, BF₃]

The linear structure is not assumed by

1. ${\mathrm{SnCl}}_2$

2. ${\mathrm{NCO}}^{-}$

3. ${\mathrm{NO}}^{+}$

4. ${\mathrm{NO}}_2^{+}$

${\mathrm{CO}}_3^{2-}$anion does not has which of the following characteristics

1. Bonds of unequal length                               

2. sp² hybridization  of c atom

3. Resonance stabilization                                   

4. Same bond angles

Which of the following process is not associated with change of hybridization of the underlined compound

1. $\underline{\mathrm{Al}}{\left(\mathrm{OH}\right)}_3$ ppt. dissolved in NaOH

2. ${\underline{\mathrm{B}}}_2{\mathrm{H}}_6$ is dissolved in THF

3. $\underline{\mathrm{Si}}{\mathrm{F}}_4$ vapour is passed through liq. HF

4. Solidification of $\underline{\mathrm{P}}{\mathrm{Cl}}_5$ vapour