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Ch.19 - Electrochemistry
Chapter 19, Problem 136c

Predict the anode, cathode, and overall cell reactions when an aqueous solution of each of the following salts is electrolyzed in a cell having inert electrodes. (c) LiOH

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Identify the ions present in the aqueous solution of LiOH: Li^+, OH^-, H_2O.
Determine the possible reactions at the anode (oxidation): Consider the oxidation of OH^- to O_2 and H_2O to O_2.
Determine the possible reactions at the cathode (reduction): Consider the reduction of Li^+ to Li and H_2O to H_2.
Compare the standard electrode potentials to determine which reactions are more favorable at the anode and cathode.
Write the overall cell reaction by combining the half-reactions from the anode and cathode.

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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 electrolytic cell, an external voltage is applied to facilitate the movement of ions in an electrolyte solution, leading to oxidation at the anode and reduction at the cathode. Understanding this process is crucial for predicting the reactions that occur during the electrolysis of a salt solution.
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Half-Reactions

Half-reactions represent the individual oxidation and reduction processes occurring at the electrodes during electrolysis. Each half-reaction shows the transfer of electrons and the species involved. For LiOH, the oxidation of hydroxide ions (OH-) and the reduction of lithium ions (Li+) must be considered to predict the overall cell reactions accurately.
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Inert Electrodes

Inert electrodes, such as platinum or graphite, do not participate in the chemical reactions occurring during electrolysis; they merely provide a surface for the reactions to take place. Their role is to facilitate the transfer of electrons without undergoing any change themselves. This is important in the context of the electrolysis of LiOH, as the reactions will depend solely on the ions present in the solution.
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