Problem 109 - A Complete Resource Book in Chemistry for JEE Main

Question

In the electrolytic cell, flow of electrons is from (a) cathode to anode in solution (b) cathode to anode through external supply (c) cathode to anode through internal supply (d) anode to cathode through internal supply

Step-by-Step Solution

Answer

(b) cathode to anode through external supply

Step 1: Electrolysis Basics

In an electrolytic cell, an external power source is used to drive a non-spontaneous chemical reaction. The power source forces electrons to move through the cell.

Step 2: Identify Electron Flow Direction

The electrons flow from the anode to the cathode. This flow is part of completing the electrical circuit between the power source and the electrolytic cell.

Step 3: Locate External Path

The electrons move through the external circuit, driven by the power source. This external path is typically composed of wires connecting the anode and cathode.

Step 4: Identify Correct Flow Direction

Given that electrons flow from the anode to the cathode externally and the question asks for flow from cathode to anode, the flow occurs through external supply for an electrolytic cell.

Key Concepts

Electron Flow Direction

In an electrolytic cell, the direction in which electrons flow is crucial to the process of electrolysis. Our primary focus is on the flow of electrons from the anode to the cathode. The anode is the site of oxidation, where negatively charged electrons are released. These released electrons then travel through the external circuit toward the cathode.

This movement is opposite to the direction of conventional current, but it is essential in completing the circuit by enabling the electron transfer that drives chemical reactions within the cell. Understanding this flow helps us to predict and manipulate the changes that occur during electrolysis, ensuring the proper function of the cell.

Electrolysis Process

Electrolysis is the fascinating process of using electrical energy to drive a chemical reaction that would not occur spontaneously. This process occurs within an electrolytic cell supported by an external power source.

• The power source provides the necessary energy, encouraging electrons to move from one electrode to the other.
• At the anode, oxidation occurs, which generates electrons.
• These electrons travel through the external circuit to reach the cathode.
• At the cathode, reduction takes place, capturing those electrons to facilitate the desired chemical reaction.

This orchestration of electron movements ensures the desired reaction progresses as planned, showcasing the intricate relationship between electricity and chemistry.

External Circuit Path

The external circuit path is a critical component of the electrolytic cell, acting as the route by which electrons travel between the anode and cathode. This path consists of conductive materials like wires that connect the power source to the cell's electrodes.

The external path ensures that electrons can effectively traverse from their point of release at the anode to their destination at the cathode.

• By providing a complete circuit, the external path allows for a continuous flow of electrons.
• This pathway is essential not only for facilitating the electrolysis process but also for preventing the buildup of charges, which could disrupt the cell's function.

Understanding the role of the external circuit is key to mastering how electrolysis and electron flow work hand in hand to drive chemical reactions in an electrolytic cell.