Traffic Light Reaction

Supplies

- Glucose:0.1M,250ml (take Glucose bottle)

- NaOH:3M,10ml (take NaOH bottle)

- Indicator: Indigo carmine

- 500ml Flask with a stopper (good stopper!) and glass rod for stiring

Procedure

In a beaker containing 250 ml of distilled water, add 3 g of dextrose and stir until it dissolves. Next, add 5 g of sodium hydroxide pellets into the same beaker, and use a stirring rod to break apart the pellets so that they will dissolve quickly. Once this is done, pour the contents of the beaker into the glass flask, and add between 5-10 ml of the indigo carmine indicator. Enough should be added to the solution so that it turns a yellow color. Put the stopper in the flask, and let it sit for ten minutes. After ten minutes, the solution should be ready for the demonstration. Shake the flask once or twice, and it should turn a red color. Shake once or twice again, and it should turn green. Then, if it sits, it should turn back to the yellow color.