traffic light experiment explained

The chemical traffic light experiment is a dramatic redox reaction that changes colors between yellow or amber, green, and red. Shaking the solution then reverses the reaction, so the color change goes from red to green to yellow (like a traffic light).

Principle: This demonstration involves a reversible oxidation-reduction reaction between I.C., oxygen (O 2), and a reducing sugar. I.C. is a both a pH and a redox indicator; the oxidized form is blue below pH 11.4, yellow above pH 13, and green in the intermediate range, while the reduced form is yellow at all pH levels.

This experiment can lead to a full-scale kinetic investigation by changing the concentration of the reactants and the catalyst. It can be used to develop a deeper understanding of non-standard electrode potentials and their use in predicting the feasibility of a reaction: 2HCO 2-(aq) + 2CO 2 (g) + 6H + (aq) + 6e-→ C 4 H 4 O 6 2-(aq) + 2H 2 O ...

Demonstration. Indigo carmine is added to a 1:1 mixture of ethanol and water. KOH is dissolved in water, dextrose (glucose) is added to this solution, along with the indicator solution.

The chem­i­cal traf­fic light is a stun­ning col­or­ful re­ac­tion! The ex­per­i­ment in­volves chang­ing col­ors with an in­di­ca­tor – in­di­go carmine in an al­ka­line so­lu­tion of glu­cose.

Also known as the traffic light reaction, indigo carmine produces a colorful demonstration. In this activity, a redox indicator (indigo carmine) changes color as a result of electron transfer. The introduction of oxygen through swirling causes the indigo carmine to turn green as it is oxidized.

19.2 The Traffic Light Demonstration. Chemical Concept Demonstrated: Reversible oxidation-reduction reactions. Demonstration: Indigo carmine is added to a 1:1 mixture of ethanol and water. KOH is dissolved in water, dextrose (glucose) is added to this solution, along with the indicator solution.

Traffic Light Reaction. In this activity, a redox indicator (indigo carmine) changes color as a result of electron transfer. The introduction of oxygen through swirling causes the indigo carmine to turn green as it is oxidized.

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Can a liq­uid change col­ors by it­self? Check out “Chem­i­cal traf­fic light” – a breath­tak­ing­ly col­or­ful re­ac­tion! Safe­ty pre­cau­tions. Wear pro­tec­tive gloves and eye­wear when work­ing with sodi­um hy­drox­ide, as it caus­es burns upon con­tact with the eyes and skin.