The correct state of hybridisation of C₂, C₃, C₅ and C₆ of the hydrocarbon 

 is in the sequence:
1. sp, sp³, sp² and sp³
2. sp³, sp², sp² and sp
3. sp, sp², sp² and sp³
4. sp, sp², sp³ and sp²

The correct order of increasing bond order among the given is:

1. ${\mathrm{O}}_2^{-}$ $<$ $\mathrm{NO}$ $<$ ${\mathrm{C}}_2^{2-}$ $<$ ${\mathrm{He}}_2^{+}$

2. $\mathrm{NO}$ $<$ ${\mathrm{C}}_2^{2-}$ $<$ ${\mathrm{O}}_2^{-}$ $<$ ${\mathrm{He}}_2^{+}$

3. ${\mathrm{C}}_2^{2-}$ $<$ ${\mathrm{He}}_2^{+}$ $<$ $\mathrm{NO}$ $<$ ${\mathrm{O}}_2^{-}$

4. ${\mathrm{He}}_2^{+}$ $<$ ${\mathrm{O}}_2^{-}$ $<$ $\mathrm{NO}$ $<$ ${\mathrm{C}}_2^{2-}$

The correct order of C-O bond length among CO, ${\mathrm{CO}}_3^{2-}$ , CO₂ is:

1. $C{O}_2<C{O}_3^{2-}<CO$

2. $CO<C{O}_3^{2-}<C{O}_2$

3. $C{O}_3^{2-}<C{O}_2<CO$

4. $CO<C{O}_2<C{O}_3^{2-}$

In which of the following molecules are all the bonds not equal?

Which of the following species has a linear shape?

1. $N{O}_2^{-}$

2. $S{O}_2$

3. $N{O}_2^{+}$

4. $O_3$

Which of the following is the most basic oxide?

1. $A{l}_2{O}_3$

2. $S{b}_2{O}_3$

3. $B{i}_2{O}_3$

4. $Se{O}_2$

Which of the following is not a correct statement?

The number of unpaired electrons in a paramagnetic diatomic molecule of an element with atomic number 16 is:

1. 2

2. 3

3. 4

4. 1

A diatomic molecule, among the following species, that only has $\mathrm{\pi }$ bonds according to the Molecular Orbital Theory (MOT) is: