Background Research
I’m sure you have hear of soda erupting once Mentos is added to it. This experiment is fun and exciting and it has made us wonder about the science behind it. Scientists still don’t have an answer. What is it that causes the eruption? Experienced scientist are still doing experiments to determine just what might be causing the eruption – is it chemical or physical change? Most would agree that it is a physical change.
Sodas contain sweeteners (sugar or artificial sweeteners), flavoring, water, and preservatives. Carbon dioxide (CO2) gas is added to the soda through a high pressure process that causes the gas to dissolve into the liquid. The CO2 gas remains suspended in the liquid and cannot expand to form more bubbles because of the high pressure. When a soda is opened, a whoosh can be heard as the pressure is relieved and the dissolved gas escapes. If you shake the soda, the gas takes some of the soda with it as it escapes the container.
In soda, the water molecules cling together around the carbon dioxide (CO2) gas bubbles. Bubbles can’t grow or form new bubbles unless this strong attraction between water molecules is weakened and the tension is broken. When the Mentos are dropped into the soda, the gum arabic in the coating of the Mentos weakens the attraction of the water molecules around the CO2 gas bubbles. As soon as the Mentos hit the soda, the carbon dioxide forms more bubbles in the tiny pores that are all over the Mentos surface. Couple this with the speed at which the Mentos are sinking to the bottom of the bottle and an eruptive blast occurs as the CO2 is released and breaks free taking much of the liquid with it.
We want to know if the different type of soda will affect the results. We will be testing Coca-Cola, Mountain Dew, Pepsi, and Sprite. We also want to know if there is a specific reason that causes for a bigger or smaller explosion. Is there a specific ingredient that causes the explosion? Does the amount of carbohydrates (sugar) affect the level of the explosion?
By Emily and Maddie
Sodas contain sweeteners (sugar or artificial sweeteners), flavoring, water, and preservatives. Carbon dioxide (CO2) gas is added to the soda through a high pressure process that causes the gas to dissolve into the liquid. The CO2 gas remains suspended in the liquid and cannot expand to form more bubbles because of the high pressure. When a soda is opened, a whoosh can be heard as the pressure is relieved and the dissolved gas escapes. If you shake the soda, the gas takes some of the soda with it as it escapes the container.
In soda, the water molecules cling together around the carbon dioxide (CO2) gas bubbles. Bubbles can’t grow or form new bubbles unless this strong attraction between water molecules is weakened and the tension is broken. When the Mentos are dropped into the soda, the gum arabic in the coating of the Mentos weakens the attraction of the water molecules around the CO2 gas bubbles. As soon as the Mentos hit the soda, the carbon dioxide forms more bubbles in the tiny pores that are all over the Mentos surface. Couple this with the speed at which the Mentos are sinking to the bottom of the bottle and an eruptive blast occurs as the CO2 is released and breaks free taking much of the liquid with it.
We want to know if the different type of soda will affect the results. We will be testing Coca-Cola, Mountain Dew, Pepsi, and Sprite. We also want to know if there is a specific reason that causes for a bigger or smaller explosion. Is there a specific ingredient that causes the explosion? Does the amount of carbohydrates (sugar) affect the level of the explosion?
By Emily and Maddie