Problem 135 - A Complete Resource Book in Chemistry for JEE Main

Question

In analogy to \(\mathrm{O}_{2}^{+}\left[\mathrm{PtF}_{6}\right]^{-}\)a compound \(\mathrm{N}_{2}^{+}\left[\mathrm{PtF}_{6}\right] Z^{-}\), will not be formed because: (a) The ionization of \(\mathrm{N}_{2}\) gas is higher than that of \(\mathrm{N}\) atom (b) The ionization of \(\mathrm{N}_{2}\) gas is lower than that of \(\mathrm{O}_{2}\) gas (c) The ionization of \(\mathrm{N}_{2}\) gas is higher than that of \(\mathrm{O}_{2}\) gas (d) none of these

Step-by-Step Solution

Answer

(c) The ionization of \(\mathrm{N}_2\) gas is higher than that of \(\mathrm{O}_2\) gas.

Step 1: Understanding the Ionization Concept

Ionization energy is the energy required to remove an electron from an atom or molecule. For the formation of the given compound, \ \(\mathrm{N}_{2}^{+}[\mathrm{PtF}_{6}]^{-}\ \), nitrogen gas must lose one electron, forming \(\mathrm{N}_{2}^{+}\). Comparing energy requirements for forming ions is crucial in deducing the correct option.

Step 2: Comparison of Ionization Energies for Molecular Nitrogen and Oxygen

To form \(\mathrm{N}_{2}^{+}[\mathrm{PtF}_{6}]^{-}\ \), \(\mathrm{N}_2\) must be ionized to \(\mathrm{N}_2^+\). The ionization energy of \(\mathrm{N}_2\) is generally higher than that of \(\mathrm{O}_2\) due to nitrogen's more stable electronic configuration resulting from its triple bond and half-filled p orbitals. This high stability in \(\mathrm{N}_2\) makes \(\mathrm{N}_2\) more resistant to losing an electron compared to \(\mathrm{O}_2\).

Step 3: Conclusion Based on Ionization Comparison

Since the ionization energy of \(\mathrm{N}_2\) is higher than \(\mathrm{O}_2\), \(\mathrm{N}_2\) is less likely to form \(\mathrm{N}_2^+\) ions compared to \(\mathrm{O}_2\) forming \(\mathrm{O}_2^+\). Therefore, the compound \(\mathrm{N}_{2}^{+}[\mathrm{PtF}_{6}]^{-}\ \) would not form because the ionization energy of \(\mathrm{N}_2\) gas is higher than that of \(\mathrm{O}_2\) gas.

Key Concepts

Molecular Nitrogen

Molecular nitrogen, represented as \(\mathrm{N}_2\), is a diatomic molecule consisting of two nitrogen atoms. These atoms are connected by a very strong triple bond, which includes one sigma bond and two pi bonds.
This triple bond imparts a high degree of stability to the \(\mathrm{N}_2\) molecule. As a result, \(\mathrm{N}_2\) is quite resistant to chemical reactions, including the process of ionization where an electron would need to be removed.
Due to this strong bond and stable arrangement, \(\mathrm{N}_2\) has a relatively high ionization energy. This means that more energy is needed to remove an electron from \(\mathrm{N}_2\) compared to other simpler molecular structures.

Molecular Oxygen

Molecular oxygen, \(\mathrm{O}_2\), is another diatomic molecule, but it has different properties from nitrogen. In \(\mathrm{O}_2\), the bonds connecting the oxygen atoms are one sigma bond and one pi bond, creating a double bond.
This structure makes \(\mathrm{O}_2\) less stable than \(\mathrm{N}_2\). Consequently, the ionization energy for \(\mathrm{O}_2\) is lower as it is easier to remove an electron from \(\mathrm{O}_2\).
The difference in bond stability arises from the electronic configuration of oxygen, which makes \(\mathrm{O}_2\) more reactive in general, and more amenable to forming ions when compared to \(\mathrm{N}_2\).

Electron Configuration

Electron configuration describes how electrons are distributed in an atom or molecule. It helps in understanding chemical reactivity and bonding.
For nitrogen atoms in \(\mathrm{N}_2\), each nitrogen has an electron configuration of \(1s^2 2s^2 2p^3\). Since nitrogen has a half-filled \(2p\) sublevel, it achieves a stable electronic configuration, contributing to the high ionization energy of \(\mathrm{N}_2\).
Oxygen atoms, on the other hand, have an electron configuration of \(1s^2 2s^2 2p^4\), and this configuration does not have the same stability as the half-filled \(2p\) of nitrogen. This difference influences their willingness to lose or gain electrons, which affects how easily they can be ionized.