Definition

Noun: A substance used in chemistry that changes color in a predictable and reversible manner depending on whether the chemical environment is oxidizing or reducing. It visually signals the redox potential of a solution.

Usage

This term is used specifically in analytical chemistry and laboratory settings. It refers to a chemical compound added to a solution to visually monitor or determine the endpoint of a redox titration or the redox state of a system. * The oxidation-reduction indicator turned blue, indicating the solution had become reducing. * Selecting the correct oxidation-reduction indicator is crucial for the accuracy of the titration.

Examples

• In the experiment, methylene blue was used as an oxidation-reduction indicator.
• The color change of the oxidation-reduction indicator signaled the completion of the electron transfer reaction.
• Researchers rely on a reliable oxidation-reduction indicator to monitor redox processes in real time.

Advanced Usage

• Potentiometric vs. Indicator Methods: While a redox electrode gives a precise numerical potential, an oxidation-reduction indicator provides a simple visual cue for the redox condition or titration endpoint.
• Formal Potential: The effectiveness of an oxidation-reduction indicator depends on its formal potential being within the steep potential change region of the titration curve.

Variants and Related Words

• Redox Indicator: A common synonym for oxidation-reduction indicator.
• Indicator (general): A broader category of substances that show a change (often in color) to reflect a condition, such as pH indicators.
• Oxidized Form: The state of the indicator molecule that has lost electrons.
• Reduced Form: The state of the indicator molecule that has gained electrons.

Synonyms

• Redox indicator

Related Phrases/Concepts

• Redox Titration: A titration method for which an oxidation-reduction indicator is commonly used.
• Endpoint Detection: The primary function of an oxidation-reduction indicator in a titration.
• Color Change Interval: The specific range of redox potential over which the indicator changes color.

Noun

1. an indicator that shows a reversible color change between oxidized and reduced forms