Is there enough carbon dioxide gas within a bottle of Coke to fill and pop a balloon?
In science class, we are in the middle of the unit on the 3 Phases of Matter: Solids, liquids and gases. Teaching science without the proper science lab and tools has been a challenge at CIA so I needed to find an interactive and fun way to teach my class using the limited resources I have in Phnom Penh...
This led to my lesson on gas and carbonation! Soda pop! This experiment allowed me to physically demonstrate what the atoms and molecules are doing within a gas and then send them off to their Khmer teachers, thirsts quenched from soda filled with about 1,000% of their daily caffeine and sugar intake! Hyper active children=no longer my problem. I am evil.
The warmer of my science lesson is usually a "Did you know??" segment related to whatever we are learning. And sometimes not. So...
Did you know...The pull ring tab was introduced in 1962 and the re-sealable top in 1965?
Coca-cola was the first soft drink to be consumed in outer space?
All porcupines float in water?
To begin my lesson I taught my students why soda is fizzy. The carbonation found in soda is a phenomenon in which carbon dioxide gas is dissolved in water using high pressure. The pressure is lowered when the soda bottle is opened, releasing the CO2 in the form of little tiny bubbles. To make it easier on the minds of my little fifth graders, I had them imagine a Giant Soda Monster squishing a gagillion of his little CO2 prisoners into a plastic bottle jail cell and the prisoners are very angry and want to escape. This was accompanied by lots of flailing hand gestures and my best evil monster voice, but I am pretty sure that from now on, whenever they open a soda, they will imagine they are helping with the release and escape of millions of tiny oppressed carbon dioxide prisoners. (Pun intended: oppression is derived from the idea of being physically weighted down!)
So how much CO2 is actually inside a bottle of soda? Well the cola in a bottle of cola is pressurized to about two atmospheres of pressure and if one could get ALL the CO2 out of the cola, it would fill a volume of about four times the volume of the cola itself. To demonstrate this, I had my students do a simple experiment using a bottle of Coke and balloons! We started by opening the bottle of Coke at room temperature, (soft drinks hold more CO2 at warmer temperatures than at colder temperatures, so if we did this experiment with cold Coke, less gas would be released.) Then we immediately fitted a balloon over the mouth of the bottle to trap all the CO2 that was released from the Coke. My students then watched in complete fascination as the gas released began to fill up the balloon. We recorded our observations and I had them predict and guess what would happen next. And of course, all good science experiments end with a bang so I had them shake the bottles as hard as they could. They discovered that there is in fact enough CO2 within a bottle of Coke to fill and pop a balloon! Science is awesome.
PS: Did you also know... Cambodia is the only place on Earth where the laws of physics and gravity do not apply? How is it possible to fit four people plus luggage on the back of a two person moto? Case and point below.
I am also working on a coffee table picture book titled "Bizarre things found on the back of a moto in Cambodia." So look forward to that.
