Question

Solution of sodium metal in liquid ammonia is strongly reducing due to the presence in solution of the following: (a) Solvated electrons (b) Sodium atoms (c) Sodium hydride (d) Sodium amide

Short answer

The presence of solvated electrons is responsible for the strongly reducing nature of the solution.

Step-by-step solution

Understanding the Context

The problem involves sodium metal dissolving in liquid ammonia. When sodium is introduced into liquid ammonia, it results in a solution that exhibits a strong reducing behavior. We need to determine the component in the solution causing this characteristic.

Identifying the Components

When sodium metal is dissolved in liquid ammonia, several species may form. These include the possibility of solvated electrons, sodium ions, sodium atoms, sodium hydride, and sodium amide.

Evaluating Solvated Electrons

Solvated electrons are free electrons that tend to exist in the solution, highly solvated by ammonia molecules. These electrons are known for providing strong reducing properties to the solution.

Analyzing Sodium Atoms

Sodium atoms, when dissolved, are less likely to remain unreacted in ammonia due to the tendency of unpaired electrons in sodium to interact with ammonia or its solvated electrons.

Considering Sodium Hydride

Sodium hydride is a compound that forms when sodium reacts with hydrogen. However, this is less likely in liquid ammonia unless specific conditions, like further hydrogen presence, are met.

Reviewing Sodium Amide

Sodium amide forms in the presence of ammonia and sodium but primarily when ammonia acts as a base. However, it's not characterized by reducing properties as strong as those seen with solvated electrons.

Concluding the Most Likely Component

The presence of solvated electrons best explains the strongly reducing nature of the solution. These solvated electrons provide the distinctive dark blue color and significant reducing abilities to the solution.

Key concepts

Reducing Agents

In chemistry, a reducing agent is a substance that donates electrons to another compound, reducing it in the process. Reducing agents are pivotal in various chemical reactions.

A reducing agent itself undergoes oxidation, while the substance it reduces gains electrons. Common reducing agents include hydrogen, metals like sodium, and certain compounds containing easily transferable electrons.

• Reducing agents are crucial for establishing charge balance in reactions.
• They are widely used in processes like organic synthesis and metal extraction.

In the realm of solvated electrons, these play a particularly powerful role, especially when sodium is dissolved in liquid ammonia and acts as a reducing agent.

Sodium in Liquid Ammonia

When sodium is dissolved in liquid ammonia, an intriguing chemical phenomenon occurs. Sodium metal, shiny and soft, interacts with the liquid ammonia, resulting in a distinctively colored solution ranging from deep blue to gold as the concentration increases.

This color transformation is due to the formation of solvated electrons. In this process, sodium loses electrons that become solvated by ammonia molecules.

• These solvated electrons are the key contributors to the solution's reducing capabilities.
• The behavior of these electrons in the solution is unique due to their high mobility and strong interaction with ammonia.

The blue coloration hints at the presence of electron clouds created by these solvated electrons, which are highly reducing.

Sodium Ammonia Solution

The sodium-ammonia solution is fascinating, primarily due to the solvated electrons that render it a strong reducing agent.

These electrons are strongly solvated, contributing significantly to the solution's reactivity. They are critical in facilitating numerous reduction reactions, especially those requiring strong reducing potentials.

• The formation of solvated electrons is a complex process, dependent on thorough mixing and proper conditions.
• The solution's distinctive color makes it not only an exciting subject for study but also useful in practical applications.

This solution model is instrumental in advancing our understanding of electron behaviors in non-aqueous solvents, marking it as a topic of significant interest in chemical research.