Debrief

During the process of performing the "Elephant Toothpaste" reaction, some obstacles came into play. As shown in the video posted on the "Materials and Procedure" page, the rate at which the reaction occurs within the graduated cylinder is much "cleaner" and "fuller" than what is shown from the experiment done for the purpose of this ISU. The chemicals stated on the information source did not give quantities of the chemicals needed, therefore making it challenging to create a great reaction. The ISU reaction serves the purpose of demonstrating a decomposition reaction and does so with great intensity. The unknown quantities of the chemicals needed are a key factor in why the reaction did not happen at an interesting speed.

In order to try and increase the rate of the reaction, many different combinations of the quantities of chemicals were used. At first, equal volumes and concentrations were used between the hydrogen peroxide and the potassium iodide. Once this did not work as well as the video, the concentration of the catalyst (potassium iodide) was doubled. The rate did not appear to change, so the concentration of the catalyst was then tripled. This concentration change increased the rate of reaction significantly, but still did not compare to the video shown on the "Materials and Procedure" page.

Once all of these combinations had been put together, a good reaction still did not come about, but it was then realized that the hydrogen peroxide that was being used could have been fairly old and diluted. Once the new 30% hydrogen peroxide was ordered, the rate at which the reaction occurred increased.

After the new hydrogen peroxide was bought, a 100 mL potassium iodide solution with a concentration of 2.4 M was mixed with 80 mL of the hydrogen peroxide. Through this trial, the reaction appeared to be very intense and was fairly entertaining.

Different types of liquid soaps were also used in several trials. The amount and type of soap used greatly affected the rate at which the bubbles came out. The final conclusion had been to use liquid "Dawn Dish Detergent" and use about 3-4 small squirts, mixed with 80 mL of 30% hydrogen peroxide. The addition of food coloring here is optional. After this is complete, 100 mL of 2.4 M potassium iodide was added. As a result, the final reaction is an entertaining visual of how hydrogen peroxide can be decomposed into oxygen gas and water.