In which one of the following molecules, the central atom said to adopt sp² hybridisation ?

1. BeF₂

2. BF₃

3. C₂H₂

4. NH₃

According to molecular orbital theory which of the following lists rank the nitrogen species in terms of increasing bond order ?

1. ${\mathrm{N}}_2^{-} < {\mathrm{N}}_2 < {\mathrm{N}}_2^{2-}$

2. ${\mathrm{N}}_2^{2-} < {\mathrm{N}}_2^{-} < {\mathrm{N}}_2$

3. ${\mathrm{N}}_2 < {\mathrm{N}}_2^{2-} <\hspace{0.17em}{\mathrm{N}}_2^{-}$

4. ${\mathrm{N}}_2^{-} < {\mathrm{N}}_2^{2-} < {\mathrm{N}}_2$

Among the following molecules/ions BF₃, NO₂^-, NH₂^- , and H₂O, the central atom is sp² hybridized in :  

1. NO₂^- and NH₂^-

2. NH₂^-  and H₂O

3. NO₂^- and H₂O

4. BF₃ and NO₂^-

Which one of the following is planar ?

1. XeF₄

2. XeO₄

3. XeO₃

4. XeO₃F₂

In ${\mathrm{PO}}_4^{3-}$ ion, the formal charge on each oxygen atom and P-O bond order respectively are :

1. -0.75, 0.6

2. -0.75, 1.0

3. -0.75, 1.25

4. -3.1, 1.25

The dielectric constant of H₂O is 80. The electrostatic force of attraction between Na⁺ and Cl^- will be

1. reduced to $\frac{1}{40}$ in water than in air

2. reduced to $\frac{1}{80}$ in water than in air

3. will be increased to 80 in water than in air

4. will remain unchanged

Which of the following is isoelectronic? 

1. ${\mathrm{CO}}_2, {\mathrm{NO}}_2$

2. ${\mathrm{NO}}_2^{-}, {\mathrm{CO}}_2$

3. ${\mathrm{CN}}^{-}, \mathrm{CO}$

4. ${\mathrm{SO}}_2, {\mathrm{CO}}_2$

The correct order of the increasing bond angles in the following triatomic species is :  

In an octahedral structure, the pair of d orbitals involved in d²sp³-hybridisation is

1. $d_{x^2-y^2}, d_{z^2}$

2. $d_{xy}, d_{x^2\mathit{-}{y}^{\mathit{2}}}$

3. $d_{{\mathrm{z}}^2}, d_{xz}$

4. $d_{xy}, d_{yz}$

Equilateral shape has

1. sp hybridisation

2. sp² hybridisation

3. sp³ hybridisation

4. dsp² hybridisation