Soda Can Density Discrepancy

Demonstrating the density of diet sodas versus regular sodas is a classic, but something unexpected happened when I placed a can of Dr. Pepper and A & W root beer in a tank of water. They didn't follow the usual pattern of results. Watch the video and please respond if you can provide an explanation for the results.

Comments

[Lori]

I am guessing that the 355mL of volume may be the problem. Is 355 mL the volume including the can or just the amount of "space" in the can for the liquid? The root beer and other pop could have more carbonation taking up the some of the liquid "space"....so the volume of the pop is actually less than 355mL?

[Lauren]

Hello Darren! My name is Lauren and I am a future science educator. I came across your blog and found it very interesting. I think that posting these videos and asking for explanations why certain things happen is a great tool to use to teach students.
My question for you is, are your students involved with the blog? If so, how useful in is it the classroom?

[Tracy]

I don't have a good explanation for why this happened, but have also had this happen. I find that I need to test all my cans before my demo to make sure they work. Did you try other cans from these same brands?

[Glen Gilchrist]

Nice video, I'll be showing this in class ;-)

Are the cans different diameters??

Glen

[Bryce McMinn Teacher]

This is Excellent
Bryce McMinn Teacher

[Bryce McMinn Meriden]

I love this demo. No better way to teach density. These results are not surprising,

Bryce McMinn Meriden

[Andrew]

More carbonic acid decreases the density of the mixture.