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Ch.19 - Electrochemistry
Chapter 19, Problem 98

How can one sketch an electrolysis cell that electroplates nickel onto other metal surfaces, labeling the anode and cathode and indicating the reactions that occur at each?

Verified step by step guidance
1
Identify the components of the electrolysis cell: anode, cathode, electrolyte solution, and power source.
Label the anode as the positive electrode where oxidation occurs, and the cathode as the negative electrode where reduction occurs.
Indicate that the anode is made of nickel, which will dissolve into the electrolyte solution as Ni^2+ ions.
Label the cathode as the metal surface to be plated with nickel, where Ni^2+ ions from the solution will gain electrons and deposit as solid nickel.
Write the half-reactions: at the anode, \( \text{Ni (s)} \rightarrow \text{Ni}^{2+} (aq) + 2e^- \); at the cathode, \( \text{Ni}^{2+} (aq) + 2e^- \rightarrow \text{Ni (s)} \).

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Electrolysis

Electrolysis is a chemical process that uses electrical energy to drive a non-spontaneous reaction. In an electrolysis cell, an external power source applies voltage to facilitate the movement of ions in an electrolyte solution, leading to chemical changes at the electrodes. This process is fundamental in electroplating, where metal ions are deposited onto a surface.
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The Electrolytic Cell

Anode and Cathode

In an electrolysis cell, the anode is the electrode where oxidation occurs, meaning it loses electrons, while the cathode is where reduction takes place, gaining electrons. For nickel electroplating, the anode typically consists of nickel metal, which dissolves into the solution as nickel ions, while the cathode is the surface being plated, where nickel ions are reduced and deposited.
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Electrolytic Cell Components Example

Half-Reactions

Half-reactions are the individual oxidation and reduction reactions that occur at the anode and cathode, respectively. In the context of nickel electroplating, the half-reaction at the anode involves the oxidation of nickel metal to nickel ions, while the cathode reaction involves the reduction of nickel ions back to solid nickel. Understanding these half-reactions is crucial for sketching the electrolysis cell accurately.
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Redox Half Reactions Example