Oxidation-Reduction of Indigo Carmine
WHY DOES THE COLOR CHANGE ?
Science concepts: Reversible Oxidation-Reduction Reactions
What is in the solution?
Sodium hydroxide – makes the solution basic
Glucose – acts as a reducing agent (loses electron)
Indigo carmine – indicator for the reaction
What is happening?
Indigo carmine can exist in oxidized (loss of electron), reduced (gain of electron) and intermediate forms.
Each form has a slightly different structure which means that each structure absorbs a different frequency of light; hence the three different colours – red, yellow and green.
Post time: Oct-06-2017