Effervescence at depth

[Deefstes]

On a recent dive trip I thought I'd fool around a little and take an effervescent tablet down with me (sealed watertight off course).

When I opened the tablet at around 15m I was disappointed to find that it didn't really errupt as I had visualised in my mind's eye and the fish didn't seem to take any notice of it. In stead the tablet simply gave off very small bubbled which formed on its surface and escaped after a while to make place for new bubbles.

Here's a picture where a Sunburst Butterflyfish came to investigate my exceedingly boring "experiment". That's about as much interest as the tablet managed to elicit.

I can only assume that the ambient pressure at 15m must have compressed the gas that forms so that, in stead of a strong stream of effervescence, it only formed tiny bubbles. Does anyone understand the mechanism of effervescence better who can offer a better explanation? Would it take the tablet longer then to dissolve at 15m than it would in a glass of water?

Yours in pointless science.

 

[seductiveconcepts]

The chemical reaction that occurs will be slowed by colder temperatures and higher pressures, while temperature isn't going to be a big concern the pressure should have certainly slowed the chemical reaction down thus slowing the bubbles.

Source:
Student Experiment 4- Pressure and Rate of Reaction

 

[Deefstes]

Cool bananas! Thanks, that makes perfect sense.

 

[almitywife]

next time take a raw egg and open it very gently underwater.... much more interesting than your little pill

 

[DandyDon]

next time take a raw egg and open it very gently underwater.... much more interesting than your little pill

Damn! Beat me to it.

Play tennis with your bud and the yoke, see who breaks it. Crabs should love the shell.

A sealed, empty, plastic beverage bottle becomes very interesting at 80+ ft.

 

[Deefstes]

Hey, that sounds interesting indeed. I'll be sure to give that a try. Don't want you to spoil the surprise and tell me what'll happen but should I do this where there are lots of fish around or is it simply an experiment about pressure etc?

 

[almitywife]

its a experiement with pressure, just be gentle when cracking open the egg and peeling the shell

and if you cant wait, i do have a youtube link

 

[Deefstes]

A sealed, empty, plastic beverage bottle becomes very interesting at 80+ ft.

I've once taken an open plastic beverage bottle down, filled it with air at 20m, sealed it and sent it up with the buoyline. Again, I was somewhat underwhelmed with the results as the bottle did not deform or anything but was just very hard. I'd like to repeat that experiment some time from 50m or so but it'll be a few years before I get to dive to that depth.

 

[Deefstes]

and if you cant wait, i do have a youtube link

No, don't spoil it for me Oh well, maybe others might be interested but I'll refrain from watching the video until I've done it myself.

Hmm, I wonder what the depth rating of a standard uncooked chicken egg is...

 

[almitywife]

the video link i have is at 20mtrs - i hear its an advance course instructor trick


personally i would like to know how to blow the bubble rings you see divers do - but i guess it helps if youre a smoker