Question

In Iron atoms, Fe, are better reducing agents than copper ions, \(\mathrm{Cu}^{2 *}\). In which direction do electrons flow when an iron nail is submerged in a solution of \(\mathrm{Cu}^{2+}\) ions?

Short answer

Electrons flow from the iron nail to the copper ions.

Step-by-step solution

Understand the Redox Reaction

In a redox reaction, one substance loses electrons and another gains them. The substance that loses electrons is the reducing agent, and the one that gains electrons is the oxidizing agent. Here, iron (Fe) is the reducing agent and copper ions ( abla_{Cu}^{2+} abla_{Cu}^{2+} abla_{Cu}^{2+}) are the oxidizing agent.

Write the Half-Reaction Equations

Write the oxidation half-reaction for iron and the reduction half-reaction for copper ions: \[ \text{Oxidation (Fe)}: \ Fe \rightarrow Fe^{2+} + 2e^- \]\[ \text{Reduction (Cu)}: \ Cu^{2+} + 2e^- \rightarrow Cu \]

Determine the Direction of Electron Flow

Electrons always flow from the reducing agent to the oxidizing agent. Since iron loses electrons (is oxidized) and copper ions gain electrons (are reduced), electrons flow from the iron nail (Fe) to the copper ions ( abla_{Cu}^{2+} abla_{Cu}^{2+} abla_{Cu}^{2+}) in the solution.

Conclusion

Based on the half-reactions, since iron is a better reducing agent, electrons move from the iron nail to the copper ions. This results in copper being deposited on the iron nail as it gains electrons.

Key concepts

Reducing Agents

Reducing agents play a crucial role in redox reactions by donating electrons to other substances. When a compound or element acts as a reducing agent, it undergoes oxidation itself. This means it loses electrons and increases its oxidation state. In the context of the exercise, iron (\( \text{Fe} \)) serves as the reducing agent. By losing electrons, iron is able to convert itself into iron ions (\( \text{Fe}^{2+} \)), facilitating electron donation.Here are a few characteristics of reducing agents:

• They are always oxidized in the reaction.
• They contribute electrons to the reaction process.
• They often contain metals or other elements capable of releasing electrons easily.

In short, reducing agents are critical for enabling the transfer of electrons to another substance, initiating the redox process.

Oxidizing Agents

Oxidizing agents are substances that receive electrons from reducing agents in a redox reaction. They undergo reduction, meaning they gain electrons and their oxidation state decreases. In the given exercise, copper ions (\( \text{Cu}^{2+} \)) act as oxidizing agents. As they receive the electrons from iron, they convert from copper ions to elemental copper (\( \text{Cu} \)).Important attributes of oxidizing agents include:

• They are reduced during the reaction, accepting electrons.
• They generally involve non-metals or positive ions.
• They often possess a high affinity for gaining electrons.

Understanding oxidizing agents is key to predicting how substances will interact in a redox scenario and determining which will gain electrons.

Electron Flow

Electron flow is central to understanding redox reactions. It refers to the movement of electrons from the reducing agent to the oxidizing agent. This flow of electrons is what drives the chemical change in a redox reaction. For instance, in the exercise:

• Electrons begin at the iron nail, since iron is the reducing agent.
• They then move through the solution to the copper ions, the oxidizing agent.
• As a result, copper gains electrons and deposits onto the iron as elemental copper.

Directionally, electrons always flow from the species that is oxidized (loses electrons) to the species that is reduced (gains electrons). By understanding the direction of electron flow, you can predict the results of a redox reaction, such as which materials will transform and into what substances they will convert.