The key difference between reduction potential and reducing power is that reduction potential refers to the ability of a chemical species to undergo reduction or oxidation whereas reducing power refers to the ability of a chemical substance to reduce another chemical species.
Reduction potential is a parameter we can use to measure the reducing power or the oxidizing power of a chemical substance. Reducing power, on the other hand, is the term that describes the ability of a chemical substance to make another substance gain electrons.
CONTENTS
1. Overview and Key Difference
2. What is Reduction Potential
3. What is Reducing Power
4. Side by Side Comparison – Reduction Potential vs Reducing Power in Tabular Form
5. Summary
What is Reduction Potential?
Reduction potential is the measurement of a chemical species’ ability to undergo either reduction or oxidation. Therefore, we can call this oxidation/reduction potential. This term refers to the ability of a chemical species to either gain or lose electrons.
Oxidation is the state of losing electrons to increase the oxidation state. Loss of electrons means there are not enough electrons to balance the positive charges of protons. Therefore, the positive nature of the chemical species increases during oxidation. The chemical species that can make other substances lose electrons are named as oxidizing agents. They undergo reduction while other species undergo oxidation.
Reduction is the state of gaining electrons to decrease the oxidation state. The gain of electrons means that there are more than enough electrons to balance the positive charges of protons. Therefore, the positive nature of the chemical species decreases during reduction. The chemical species that can make other substances gain electrons are called reducing agents. Here, they undergo oxidation while other species undergo reduction.
Figure 01: A Simple Apparatus that Can Be Used to Measure Reduction Potential
The reduction potential is a quantitative measurement of the oxidizing or reducing power. We can measure it in volts (V), or millivolts (mV). Usually, each chemical species has its own intrinsic reduction potential value. The reduction potential explains the affinity for electrons. E.g. more positive the reduction potential, greater the affinity for electrons.
What is Reducing Power?
Reducing power is the ability of a chemical species to make another chemical substance undergo reduction. The chemical substances that have this ability are named reducing agents. Reducing agent undergoes oxidation while the other substance undergoes reduction. This means the reducing agent can donate electrons to another chemical species and eventually make it undergo reduction.
Figure 02: Standard Reduction Potentials of Some Chemical Species
The reducing power refers to the tendency of the chemical species to reduce another element; e.g. higher the reducing power, more easily a chemical species can reduce another substance.
What is the Difference Between Reduction Potential and Reducing Power?
Although the terms reduction potential and reducing power sound similar, their meanings are different from each other. The key difference between reduction potential and reducing power is that reduction potential refers to the ability of a chemical species to undergo reduction or oxidation whereas reducing power refers to the ability of a chemical substance to reduce another chemical species.
Below infographic summarizes the difference between reduction potential and reducing power.
Summary – Reduction Potential vs Reducing Power
Although the terms reduction potential and reducing power sound similar, their meanings are different from each other. The key difference between reduction potential and reducing power is that reduction potential refers to the ability of a chemical species to undergo reduction or oxidation whereas reducing power refers to the ability of a chemical substance to reduce another chemical species.
Reference:
1. Helmenstine, Anne Marie. “Standard Reduction Potential Definition.” ThoughtCo, Sep. 3, 2019, Available here.
Image Courtesy:
1. “Standard electrode potential of zinc” By Andyrendall – Own work (Public Domain) via Commons Wikimedia
2. “Standardpotentials” By Tem5psu – Own work (CC BY-SA 3.0) via Commons Wikimedia