- Source: Redox indicator
A redox indicator (also called an oxidation-reduction indicator) is an indicator which undergoes a definite color change at a specific electrode potential.
The requirement for fast and reversible color change means that the oxidation-reduction equilibrium for an indicator redox system needs to be established very quickly. Therefore, only a few classes of organic redox systems can be used for indicator purposes.
There are two common classes of redox indicators:
metal complexes of phenanthroline and bipyridine. In these systems, the metal changes oxidation state.
organic redox systems such as methylene blue. In these systems, a proton participates in the redox reaction. Therefore, sometimes redox indicators are also divided into two general groups: independent or dependent on pH.
The most common redox indicator are organic compounds.
Redox Indicator example:
The molecule 2,2'- Bipyridine is a redox Indicator. In solution, it changes from light blue to red at an electrode potential of 0.97 V.
pH independent
pH dependent
See also
Chemical analysis
pH indicator
Complexometric indicator
References
External links
Redox Indicators. Characteristics And Applications
Kata Kunci Pencarian:
- Indikator redoks
- Hidrogen peroksida
- Arsen
- Redox indicator
- PH indicator
- Redox titration
- Ferroin
- Indicator
- Methylene blue
- Titration
- Diphenylamine
- Complexometric indicator
- Safranin