How can I recreate this pressure boiling experiment

Click For Summary

Discussion Overview

The discussion revolves around recreating a pressure boiling experiment at home, focusing on the necessary equipment, safety considerations, and methods for achieving the desired vacuum conditions. Participants explore both theoretical and practical aspects of the experiment.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Experimental/applied

Main Points Raised

  • Harry inquires about the parts needed to safely recreate a pressure boiling experiment at home.
  • Some participants express concern about safety, suggesting that Harry may lack the necessary expertise to conduct the experiment safely.
  • There are discussions about the risks associated with creating a vacuum, particularly the potential for implosion, with some noting that the vacuum required for the experiment is relatively mild.
  • One participant suggests using a water pump and epoxy to create a vacuum enclosure, while expressing surprise at the low vacuum pressure needed for water to evaporate.
  • Another participant explains that the vacuum caused by the aspirator is limited by the vapor pressure of water, indicating a need to reduce pressure to about 1 kPa for evaporation to occur.
  • A suggestion is made to use a syringe to demonstrate the boiling effect with hot water, although Harry expresses a desire to scale this up to match the original experiment.
  • Further clarification is provided regarding the pressure levels achievable with a water pump and the implications for implosion risk.

Areas of Agreement / Disagreement

Participants express varying levels of concern regarding safety and feasibility, with no consensus on the best approach to recreate the experiment. Some participants agree on the basic principles of vacuum creation, while others emphasize the risks involved.

Contextual Notes

Participants discuss the limitations of the vacuum enclosure suggested and the dependence on specific equipment and conditions for safe execution of the experiment. The discussion reflects uncertainty about the safety measures required and the effectiveness of different methods proposed.

cazzuey
Messages
10
Reaction score
0
Hi all,

I was just wondering how I could recreate this at home
What parts do I need?

Thanks,
Harry
 
Chemistry news on Phys.org
I'm afraid if you have to ask, you don't have the expertise to do this safely. Sorry.
 
Vanadium 50 said:
I'm afraid if you have to ask, you don't have the expertise to do this safely. Sorry.

What are the safety risks?
 
cazzuey said:
What are the safety risks?
Well normally pulling a vacuum involves an implosion risk. That jar is not a good vacuum enclosure. But the simple water pump mechanism being used in the video pulls a pretty mild vacuum, so the implosion risk is probably minimal.

Get the water pump thing, and use epoxy to fasten a nipple onto a jar lid, I guess. I'm surprised that it takes such a soft vacuum to cause the water to evaporate like that.
 
  • Like
Likes   Reactions: cazzuey
berkeman said:
Get the water pump thing, and use epoxy to fasten a nipple onto a jar lid, I guess. I'm surprised that it takes such a soft vacuum to cause the water to evaporate like that.

I was to, but some intelligent folks on here cleared it up for me; the vacuum caused by the aspirator is only limited by the vapour pressure of water. Basically, I need to get the pressure down to about 1kPa at room temp for evaporation to occur.

I was mostly wondering what the tubing he uses is called so I could get my hands on some. Also, I plan to add another chamber where the evaporated water can collect.

Thanks again all
 
Why did you create a second thread on the same subject? That is against the PF rules...
 
berkeman said:
Why did you create a second thread on the same subject? That is against the PF rules...

I asked how I could recreate it here - In the other one I asked about how the pump works. Sorry if I broke the rules. You can ban me or whatever the punishment is. Thanks for the help.
 
Take a syringe - the larger, the better. Suck a bit of hot water inside, plug the hole (even with a finger), pull the piston. Water will boil instantly, even if for a very short period of time. That's exactly the same effect.
 
  • Like
Likes   Reactions: berkeman
Borek said:
Take a syringe - the larger, the better. Suck a bit of hot water inside, plug the hole (even with a finger), pull the piston. Water will boil instantly, even if for a very short period of time. That's exactly the same effect.

I need to do it on a bigger scale like in the video.
 
  • #10
berkeman said:
But the simple water pump mechanism being used in the video pulls a pretty mild vacuum, so the implosion risk is probably minimal.
A water pump can get you near as low as the vapour pressure of water which is about 20 mbar while the outside pressure on the vessel is 1 bar.
Hence the pressure difference acting on the vessel is nearly 1 bar which is all what counts in terms of implosion risk. Even with a high vacuum pump it won't be higher.
 
  • #11
DrDu said:
A water pump can get you near as low as the vapour pressure of water which is about 20 mbar while the outside pressure on the vessel is 1 bar.
Hence the pressure difference acting on the vessel is nearly 1 bar which is all what counts in terms of implosion risk. Even with a high vacuum pump it won't be higher.
In that case, this thread is closed.
 

Similar threads

Vapor pressure -- How does water still boil at 100°C in an open pot?
  • · Replies 35 ·
2
Replies
35
Views
6K
Looking for a chemical with a boiling point between 10C and 50C
  • · Replies 4 ·
Replies
4
Views
3K
Does pressure affect equilibrium vapor pressure (or RH)?
  • · Replies 8 ·
Replies
8
Views
3K
After Dissolving Salt in Boiling Water, How Do You Get it Back?
  • · Replies 18 ·
Replies
18
Views
7K
How can water be boiled without using heat?
  • · Replies 21 ·
Replies
21
Views
6K
Understanding the Difference Between Evaporation and Boiling
  • · Replies 1 ·
Replies
1
Views
3K
Undergrad Heat pumps: Questions about compressor pump refrigerant gas and evaporator
  • · Replies 30 ·
2
Replies
30
Views
5K
Fractional distillation calculations
  • · Replies 1 ·
Replies
1
Views
2K
What is the Chemistry Behind Refrigerant Blends?
  • · Replies 6 ·
Replies
6
Views
4K
High School Cheapest equipment to boil water at 60℃
  • · Replies 15 ·
Replies
15
Views
4K