Curiouser and Curiouser (1 Viewer)

[Butterflygirl02]

Hello,
I'm doing a science fair experiment with my 6 year old to determine whether different brands of cola drink have different amounts of carbon dioxide in them. We thought (clearly foolishly) that we could mark the side of the bottle with the liquid level, open the bottle and let it go flat, then mark the new level and determine the volume difference. Having read a little more on this forum I realise now that we should weigh it rather than use the liquid level. But we've had an unexpected result in that the liquid level in the opened bottle is higher than in the unopened bottle. I'm at a loss to explain it, can anyone here? I know liquid does not compress (much? at all?) under pressure, so I would not have thought that would be the cause, but am I wrong about that?
Thanks!

 

[seventhroot]

what do you mean that the liquid rose more? matter cannot be created out of nothing (law of conversation of matter lol). can you state your method in a bit more detail?

 

[Butterflygirl02]

I'm not suggesting that matter has been magically created in the bottle. I am sure there is an explanation, just wondering what it is. We had an unopened bottle of coke, marked the liquid level on the side with a pen, opened the bottle and the liquid level is now above the pen mark. Something to do with the release of pressure and the creation of bubbles perhaps, but not the result I was expecting and I thought someone here might have some insight.

 

[seventhroot]

well something external stuff could have happened. some reasons like:

- the bottle contracted
- inaccurate calibration, I mean making a small mark is not the best option.
- the gas (CO2) [I can't remember much from chemistry] but maybe there was a chemical reaction and the air around it did something
- etc etc

I would suggest measuring in a controlled environment and all that for accurate and valid results but this may be beyond year 6 science

 

[Butterflygirl02]

We did it on three bottles, different types of cola, happened on all of them. The liquid is significantly above the mark and when next to an unopened bottle it is above the level in the unopened bottle. I'm not actually looking for an explanation for my 6 year old, I would like to know for myself!

 

[seventhroot]

IMO; I think it is something to do with an external factor but not something like "matter was created"

It would be a good idea to wait for someone who knows a bit more chemistry that I do; didn't help when you posted in the Physics forum. will be answered eventually

 

[Queenroot]

Why is this in the physics section?

Anyway, it's probably just condensed water or something.