Gases dissolved in water
A simple experiment to show that there are really gases dissolved in water.
Luckily, my parents like to play at least as much as I do. So when I got back from doing “real science” in Bergen the other day, they picked me up at the airport and showed me their latest toys: Vacuum pumps! [edit: Not really vacuum vacuum, but at least much lower than atmospheric pressure. And apparently those pumps are sold with the original purpose of re-sealing wine bottles]
Vacuum pumps are great to show that there are actually gases dissolved in water, because oftentimes that isn’t all that obvious. But when the pressure of the head space of a bottle is decreased, gases that were happily dissolved under atmospheric pressure start coming out of solution.
Gas being bubbled out of water by decreasing the pressure of the head space of the bottle.
Here is a comparison of normal tap water and sparkling water (sparkling water obviously containing much more dissolved CO2 than tap water, hence more bubbling).
Bubble size depending on pressure | says:
[…] this post, we talked about how decreasing the pressure on water can make dissolved gases come out of […]
Vacuum pumps – Mirjam S. Glessmer says:
[…] pumps (“vacuum” being used in a loose sense of the word…) on water in this post, we obviously had to make sure they worked. And can you guess how you best test […]
Joe Navy says:
Very excellent Dr. Glessmer. Thank you parents for bringing you into a world of hands-on experimentation so that you could discover the joy!
I’ll need to be purchasing one of these for my science demo kit (and kitchen of course).