Let’s make a ROCKET

 

In the Diet Coke and Mentos Lab, we first prepared our base by cutting half of an empty bottle and setting in down into the tray. We then took 5 mentos and connected them to a sharp nail. We poked that nail into a cork and then inserted it into the bottle hole. When we were ready, we flipped the entire bottle upside down and stuck it into the base. The pressure from the CO2 in the bottle had enough power to propel the bottle in an upward motion. This is how we made our rocket.

Here is a step by step picture:

Questions

Reference any chemical/physical reaction that may have occurred

The diet coke and mentos experiment is a physical reaction.

All the carbon dioxide in the soda that is squeezed into the liquid wants to escape. Additionally, the CO2 clings on to any tiny bumps that it can grab onto. Those tiny bumps are called nucleation sites: places the gas can grab onto and start forming bubbles. Nucleation sites can be are anywhere that there is a high surface area in a very small volume. The surface of a Mentos is sprayed with layers of liquid sugar. That makes it not only sweet but also covered with lots and lots of nucleation sites. In other words, there are so many microscopic areas on the surface of a Mentos that an incredible number of bubbles will form around the Mentos when you drop it into a bottle of soda. Since the Mentos are also heavy enough to sink, they react with the soda all the way to the bottom. The escaping bubbles quickly turn into a raging foam, and the pressure builds dramatically.

This is why it launched!

 

Thoughts on WHY the rocket launched

All of the CO2 in the soda was immediately released causing a load of pressure to escape from the bottom when the cork busted out.

 

How any gas laws are involved

Boyle’s Laws is involved. When the mentos react with the mentos, the pressure in the bottle rises to a higher level than the outside compressing the coke in the bottle. Once it is released into normal atmospheric pressure the coke rises in volume and the pressure is lost as it is propelled upward.

 

Ideas of what went wrong or what could improve the launch

I think the cork didn’t allow for a powerful launch. The cork wasn’t really completing a good seal, thus the rocket didn’t build up very much pressure.

I am also curious whether or not fruit flavored mentos will have a different reaction than the mint flavored ones.

 

Lastly, I leave you with a video of what the reaction looked like. Unfortunately, the cameraman in our team wasn’t prepared, so we have a quick representation of what the reaction looked like. Sorry for not catching the rocket on camera.