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Ch.20 - Electrochemistry
All textbooksBrown 14th EditionCh.20 - ElectrochemistryProblem 34
Chapter 20, Problem 34

What conditions must be met for a reduction potential to be considered a standard reduction potential?

Verified step by step guidance
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Understand that a standard reduction potential is a measure of the tendency of a chemical species to gain electrons and be reduced. It is measured under specific conditions to ensure consistency and comparability.
Recognize that the standard reduction potential is measured at a temperature of 298 K (25°C). This is the standard temperature for most thermodynamic measurements.
Identify that the pressure must be 1 atmosphere (atm) for gases involved in the reaction. This standard pressure ensures that the behavior of gases is consistent across different measurements.
Note that the concentration of any aqueous solutions involved in the reaction must be 1 molar (1 M). This standard concentration allows for consistent interaction between ions in solution.
Understand that the standard reduction potential is measured relative to the standard hydrogen electrode (SHE), which is assigned a potential of 0 volts. This provides a reference point for comparing the reduction potentials of different species.

Key Concepts

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

Standard Conditions

Standard reduction potentials are measured under specific conditions, typically at a temperature of 25°C (298 K), a pressure of 1 atm, and a concentration of 1 M for all reactants and products. These conditions ensure consistency and comparability of the reduction potentials across different half-reactions.
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Electrode Potential

The reduction potential of a half-reaction is a measure of its tendency to gain electrons, expressed in volts. A higher (more positive) reduction potential indicates a greater likelihood of reduction occurring, while a lower (more negative) potential suggests a lesser tendency. This potential is crucial for predicting the direction of redox reactions.
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Reference Electrode

Standard reduction potentials are often referenced against the standard hydrogen electrode (SHE), which is assigned a potential of 0.00 V. This reference point allows for the comparison of different half-reactions, as the SHE serves as a universal benchmark for measuring the tendency of other species to be reduced.
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Related Practice
Textbook Question

(b) Write the half-reaction that occurs at a hydrogen electrode in acidic aqueous solution when it serves as the anode of a voltaic cell.

Textbook Question

(c) Why is it impossible to measure the standard reduction potential of a single half-reaction?

Textbook Question

A voltaic cell that uses the reaction PdCl42-(aq) + Cd(s) → Pd(s) + 4 Cl-(aq) + Cd2+(aq) has a measured standard cell potential of +1.03 V. (a) Write the two half-cell reactions.

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