Which one of the following orders is correct for the bond dissociation enthalpy of halogen molecules?

1. Cl₂ > Br₂ > F₂ > I₂

2. Br₂ > I₂ > F₂ > Cl₂

3. F₂ > Cl₂ > Br₂ > I₂

4. I₂ > Br₂ > Cl₂ > F₂

 Which of the following pairs of ions are isoelectronic and isostructural?

$$\begin{gathered} \left(\mathrm{a}\right)<mspace\; width="1em"></mspace>{\mathrm{CO}}_3^{2-},<mspace\; width="1em"></mspace>{\mathrm{SO}}_3^{2-}<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>\left(\mathrm{b}\right)<mspace\; width="1em"></mspace>{\mathrm{ClO}}_3^{-},<mspace\; width="1em"></mspace>{\mathrm{CO}}_3^{2-} \\ \left(\mathrm{c}\right)<mspace\; width="1em"></mspace>{\mathrm{SO}}_3^{2-},<mspace\; width="1em"></mspace>{\mathrm{NO}}_3^{2-}<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>\left(\mathrm{d}\right)<mspace\; width="1em"></mspace>{\mathrm{ClO}}_3^{-},<mspace\; width="1em"></mspace>{\mathrm{SO}}_3^{2-} \end{gathered}$$

The correct bond order in the following species is

1. ${\mathrm{O}}_2^{2+}>{\mathrm{O}}_2^{+}>{\mathrm{O}}_2^{-}$

2. ${\mathrm{O}}_2^{2+}<{\mathrm{O}}_2^{-}<{\mathrm{O}}_2^{+}$

3. ${\mathrm{O}}_2^{+}>{\mathrm{O}}_2^{-}<{\mathrm{O}}_2^{2+}$

4. ${\mathrm{O}}_2^{-}<{\mathrm{O}}_2^{+}>{\mathrm{O}}_2^{2+}$

The total number of $\mathrm{\pi }$-bond electrons in the following structure is

1. 4       

2. 8         

3. 12         

4. 16

In which of the following pairs, both the species are not isostructural?

1. ${\mathrm{SiCl}}_4,<mspace\; width="1em"></mspace>{\mathrm{PCl}}_4^{+}$

2. Diamond, silicon carbide

3. ${\mathrm{NH}}_3,<mspace\; width="1em"></mspace>{\mathrm{PH}}_3$

4. ${\mathrm{XeF}}_4,<mspace\; width="1em"></mspace>{\mathrm{XeO}}_4$

Decreasing order of stability of ${\mathrm{O}}_2,<mspace\; width="1em"></mspace>{\mathrm{O}}_2^{-},<mspace\; width="1em"></mspace>{\mathrm{O}}_2^{+}<mspace\; width="1em"></mspace>\mathrm{and}<mspace\; width="1em"></mspace>{\mathrm{O}}_2^{2-}<mspace\; width="1em"></mspace>\mathrm{is:}$

1. ${\mathrm{O}}_2^{+}<mspace\; width="1em"></mspace>><mspace\; width="1em"></mspace>{\mathrm{O}}_2<mspace\; width="1em"></mspace>><mspace\; width="1em"></mspace>{\mathrm{O}}_2^{-}<mspace\; width="1em"></mspace>><mspace\; width="1em"></mspace>{\mathrm{O}}_2^{2-}$

2. ${\mathrm{O}}_2^{2-}<mspace\; width="1em"></mspace>><mspace\; width="1em"></mspace>{\mathrm{O}}_2^{-}<mspace\; width="1em"></mspace>><mspace\; width="1em"></mspace>{\mathrm{O}}_2^{}<mspace\; width="1em"></mspace>><mspace\; width="1em"></mspace>{\mathrm{O}}_2^{+}$

3. ${\mathrm{O}}_2^{}<mspace\; width="1em"></mspace>><mspace\; width="1em"></mspace>{\mathrm{O}}_2^{+}<mspace\; width="1em"></mspace>><mspace\; width="1em"></mspace>{\mathrm{O}}_2^{2-}<mspace\; width="1em"></mspace>><mspace\; width="1em"></mspace>{\mathrm{O}}_2^{-}$

4. ${\mathrm{O}}_2^{-}<mspace\; width="1em"></mspace>><mspace\; width="1em"></mspace>{\mathrm{O}}_2^{2-}<mspace\; width="1em"></mspace>><mspace\; width="1em"></mspace>{\mathrm{O}}_2^{+}<mspace\; width="1em"></mspace>><mspace\; width="1em"></mspace>{\mathrm{O}}_2^{}$

The pair of compounds that can exist together is

1. FeCl₃, SnCl₂             

2. HgCl₂, SnCl₂

3. FeCl₂, SnCl₂             

4. FeCl₃, KI

Which among the following species has a triangular planar shape?

Dipole-induced dipole interactions are present in which of the following pairs?

1. H₂O and alcohol                       

2. Cl₂ and CCl₄

3. HCl and He atoms                     

4. SiF₄ and He atoms

Which one of the following molecules contain no $\mathrm{\pi }$ -bond?

1. CO₂

2. H₂O

3. SO₂

4. NO₂