Problem 61 Describe galvanic cells that use... [FREE SOLUTION] (2024)

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In every galvanic cell, there are two primary components: the anode and the cathode. Identifying which is which is integral to understanding the cell's operation.

• Anode: This is the site where oxidation occurs. Electrons are released from the substance at the anode, marking this electrode as negative in charge within a galvanic cell. For example, in the reaction between copper and chromium, chromium ( \( \text{Cr}(s) \)) serves as the anode, as it is oxidized to \( \text{Cr}^{3+}(aq) \).
• Cathode: This is where reduction takes place. Electrons enter a substance at the cathode, which is positive in a galvanic cell. In the same example, copper ions ( \( \text{Cu}^{2+}(aq) \)) are reduced to copper metal ( \( \text{Cu}(s) \)), making this the cathode.

Always ensure to distinctly label these electrodes to correctly understand the electron flow and roles within the cell.

A half-reaction demonstrates either the oxidation or reduction process of a redox reaction, split into its separate components. This division helps in balancing the number of electrons transferred in a full reaction.

• Oxidation Half-Reaction: Represents the loss of electrons. An example would be the chromium solid ( \( \text{Cr}(s) \)) being oxidized to chromium ion ( \( \text{Cr}^{3+}(aq) \)): \[ \text{Cr}(s) \rightarrow \text{Cr}^{3+}(aq) + 3e^- \].
• Reduction Half-Reaction: Displays the gain of electrons. For instance, the transformation of copper ions ( \( \text{Cu}^{2+}(aq) \)) to copper solid ( \( \text{Cu}(s) \)): \[ \text{Cu}^{2+}(aq) + 2e^- \rightarrow \text{Cu}(s) \].

Breaking the reaction into half-reactions is vital for analyzing and designing electrochemical cells.

Understanding electron flow in galvanic cells is key to grasping how these cells function.

• Electrons always flow from the anode to the cathode through the external circuit. This movement provides the current that can do electrical work, such as lighting a bulb or powering a device.
• In the copper-chromium cell, electrons are released from the oxidation of chromium at the anode and travel through the wire to the cathode, where they are consumed in the reduction of copper ions.
• Ions in the solution flow through a salt bridge to balance the charge between the two solutions, allowing the process to continue in equilibrium.

Keeping these principles in mind ensures the proper interpretation and application of galvanic cells in various contexts.