Question

Which of the following statements are correct for the nitrogen molecule? (a) It is a good ligand (b) The bond order is \(2.2\) (c) It easily reacts with magnesium even at room temperature (d) It is used in the Serpeck's process

Short answer

Statement (d) is correct: N₂ is used in the Serpeck's process.

Step-by-step solution

Evaluate Ligand Property

A ligand is a molecule that can donate a pair of electrons to a metal atom or ion. Consider whether the nitrogen molecule (N₂) commonly acts as a ligand. Nitrogen gas is generally inert and does not readily donate electrons, so it is not considered a good ligand.

Determine Bond Order

The bond order of a molecule can be determined from molecular orbital theory. For the nitrogen molecule (N₂), the bond order is calculated as follows: There are 10 bonding electrons and 4 antibonding electrons.Bond order formula: \( \text{Bond order} = \frac{\text{(Number of bonding electrons - Number of antibonding electrons)}}{2} \) Thus, for N₂, \( \text{Bond order} = \frac{10 - 4}{2} = 3 \). The bond order of nitrogen is 3, not 2.2.

Reactivity with Magnesium

Evaluate the reactivity of nitrogen with magnesium. Nitrogen gas is very stable due to its triple bond, and it does not easily react at room temperature. Special conditions, like heating or using a catalyst, are required for nitrogen to react with magnesium or other metals.

Use in the Serpeck's Process

Serpeck's process is a method used to refine bauxite. The process involves heating bauxite with coke and nitrogen gas to produce aluminum nitride. Thus, nitrogen gas (N₂) is indeed involved in the Serpeck's process.

Key concepts

Understanding Bond Order in Nitrogen Molecule

The bond order of a molecule gives us an idea of the stability and strength of the bonds between atoms. In the case of the nitrogen molecule (N₂), it's essential to appreciate the foundational aspects that make it one of the strongest diatomic molecules. Nitrogen gas has a bond order of 3, as calculated through molecular orbital theory. This is because it possesses 10 electrons in bonding orbitals and 4 in antibonding orbitals. Using the bond order formula:\[ \text{Bond order} = \frac{10 - 4}{2} = 3 \]A bond order of 3 indicates a triple bond, which is extremely strong and stable. This is why nitrogen gas is so inert and unreactive under standard conditions. This high bond order is part of what gives the nitrogen molecule its characteristic stability and low reactivity, making it an essential component of the Earth's atmosphere.

Ligand Property of Nitrogen

To understand the ligand properties of nitrogen, we need to delve into what makes a good ligand. Ligands are species that can donate a pair of electrons to a central metal atom or ion, forming a coordinate bond.However, nitrogen in its diatomic form \(N_2\) is generally not a good ligand. The reason lies in its electron configuration and inertness. Nitrogen molecules are stable due to the strong triple bond that exists within them, making them less likely to donate electrons readily.Also, when molecules want to act as ligands, they typically need to have lone pairs of electrons that aren't tightly held. For N₂, all the electrons are involved in bonding or are not available for donation, contributing to its overall lack of reactivity as a ligand.

Nitrogen's Reactivity with Magnesium

Evaluating nitrogen's reactivity requires consideration of its chemical behavior. Nitrogen gas is notoriously unreactive due to its strong triple bond. Under normal conditions, it doesn't react with magnesium or most other metals. For a reaction to occur between nitrogen and magnesium, high temperatures or a catalyst are needed to break the strong N≡N bonds. When these conditions are met, magnesium nitride (Mg₃N₂) can form. This reaction is not common at room temperature, emphasizing nitrogen's resistance to reacting with magnesium consistently without special conditions. This stability and requirement for special conditions make the nitrogen molecule a challenging reactant in most chemical processes, needing the right environmental setup to engage in chemical reactions.

The Role of Nitrogen in Serpeck's Process

Nitrogen plays a crucial role in the Serpeck’s process, a method utilized to refine bauxite ore and obtain aluminum nitride. In this process, bauxite is mixed with coke and subjected to high temperatures in the presence of nitrogen gas. Here's a breakdown of why nitrogen is essential in this context:

• When heated with coke, the nitrogen gas reacts with aluminum compounds in bauxite to form aluminum nitride (AlN). This is a critical step in the purification and production of aluminum using this method.
• The presence of nitrogen helps in driving the reaction forward, ensuring the conversion of bauxite's aluminum oxide content into aluminum nitride effectively.
• Aside from Serpeck’s process, nitrogen's inclusion in this reaction showcases its usefulness in industrial processes where specific nitrides are desired.

Thus, nitrogen's involvement in Serpeck's process highlights its utility in chemical industry applications, going beyond its typical inert nature to serve a functional purpose in metal refining.