Which of the following is paramagnetic?

1.  CO

2.  ${\mathrm{O}}_2^{-}$

3.  ${\mathrm{CN}}^{-}$

4.  ${\mathrm{NO}}^{+}$

The isoelectronic pair of ions is                             

1. Sn²⁺ and V³⁺

2. Mn²⁺ and Fe³⁺

3. Mn³⁺ and Fe²⁺

4. Ni³⁺ and Fe²⁺

The compound among NH₃, BCl₃, Cl₂ and N₂, that does not satisfy the octet rule is:

1. NH₃

2. BCl₃

3. Cl₂

4. N₂

The largest bond angle at the central atom among the following  is:

1. CO₂

2. POCl₃

3. BCl₃

4. SO₃

The bond order for a species with the configuration $\sigma 1s^2<mspace\; width="1em"></mspace>\sigma *1s^2<mspace\; width="1em"></mspace>\sigma 2s^2<mspace\; width="1em"></mspace>\sigma *2s^2<mspace\; width="1em"></mspace>\sigma {{\rho }^1}_x$ will be:

1.  1

2.  $\frac{1}{2}$

3.  Zero

4.  \(\frac{3}{2}\)

Match the species in Column I with the 5 types of hybrid orbitals given  in Column II:

1. (1) → (a), (2) → (b), (3) → (e), (4) → (d)

2. (1) → (c), (2) → (a), (3) → (e), (4) → (d)

3. (1) → (d), (2) → (a), (3) → (e), (4) → (c)

4. (1) → (e), (2) → (b), (3) → (c), (4) → (d)

Identify the species in which the central atom exhibits \(sp^2\) hybridization:

1. \(PH_3\)
2. \(NH_3\)
3. \(CH_3^+\)
4. \(SbH_3\)

The number of sigma ($\mathrm{\sigma }$) and pi ($\mathrm{\pi }$) bonds in pent-2-en-4-yne is:

1. 13 $\mathrm{\sigma }$ bonds and no $\mathrm{\pi }$ bond

2. 10 $\mathrm{\sigma }$ bonds and 3 $\mathrm{\pi }$ bonds

3. 8 $\mathrm{\sigma }$ bonds and 5 $\mathrm{\pi }$ bonds

4. 11 $\mathrm{\sigma }$ bonds and 2 $\mathrm{\pi }$ bonds

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

In a chemical change from PCl₃ $\to$ PCl₅ the hybrid state of P changes from :

1. sp² to sp³

2. sp³ to sp²

3. sp³ to sp³d

4. sp³ to dsp