[LucianoCorr]

Hi there, I am new to these forums. I hope I am posting in the right place.

I am doing a presentation of clathrate hydrates and would like to do at least 1 of 2 things:

1. Form a clathrate compound from canned air and water

[YOUTUBE]http://www.youtube.com/watch?v=4rZJlTGMCuM[/YOUTUBE]


2. Prepare propane clathrate (or propane hydrate)

Propane Clathrate high school experiment/demo

However, I am concerned as to what materials I can use.

For the canned air/water clathrate formation the guy in the video uses a seltzer bottle.. It looks like a pop bottle, usually those can have a psi threshold of around 100. However, I do not want to approach the limit for the safety of myself and classroom. That bottle seems to have no trouble holding the pressure though. Are there alternatives?

And for the propane clathrate formation, I am wondering what I can use as  a "sample cell" that will allow sufficient pressure to allow propane clathrates to form.

Any help would be greatly appreciated. Let me know if you need more clarification

[LucianoCorr]

Πσ ħεLρ γετ ?

[billnotgatez]

Your first link will take some time to watch and needs copy and paste
your second link is not working
you might get more interest if you give a short synopsis of each link

It might take a few days for someone who is experienced in the field to sign on.

[LucianoCorr]

http://kulturo.net/dokumentoj/D-AcomData/Documents/SRJC/Development%20CHEM4A-4B%20Manual/prado-chlatrates.pdf

link should work.

http://www.youtube.com/watch?v=4rZJlTGMCuM

[LucianoCorr]

I was able to replicate the experiment in the video using a standard coke bottle and difluoroethane.

[billnotgatez]

Excellent
Could you give a very brief description for those of us who do not have patience for long videos
I now have some time so I am going to watch the youtube one

Some additional links for those interested
http://en.wikipedia.org/wiki/Clathrates
http://en.wikipedia.org/wiki/Methane_clathrate

By the way there are no shortages of exploding soda bottles on youtube.

[LucianoCorr]

It's a very simple experiment. Canned air is typically difluoroethane. When sprayed upside down the liquid will come out. With some water at the bottom of the pop bottle, spray canned air upside down into it. I waited until I could see the liquid difluoroethane boiling in the bottle.

Then I sealed the bottle and shook it. You may be worried about the bottle popping, but clathrate formation will actually greatly reduce the pressure inside of the bottle because the gas volume is greatly reduced in its hydrate form. Shake it vigorously and you should see a slushly white material form. At this point you can depressurize the bottle and listen/watch the clathrate decompose back into water and gas.

This seems like a pretty safe experiment. There is no chemical reaction occurring between the water and gas, rather they are associating with each other to form stable clathrates. I would still suggest to wash your hands after if you touch it because other substances are in canned air as well, such as bittarants to deter inhalent abuse.

Also, do this outside preferably. You do not want to inhale too much of this gas as it can cause problems. Also, if the weather is cold like it is here (-9°C atm) you can just leave the bottle outside and the difluoroethane hydrate should remain relatively stable at atmospheric pressure (1 atm).