Boiling water - oscillation; when oxygen needs more room

In summary, when boiling water, the vapour pressure becomes equal to the ambient pressure and the bubbles suddenly release.
  • #1
Mallignamius
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I understand that when the oxygen molecules are heated up in a pot of water, they will vibrate increasingly as they get hotter. I guess that's what those little bubbles are at the bottom of the pot.

At some point, they will suddenly release. Is there a name for this threshold and a way to measure it? And am I correct in thinking that they are pushed up once they reach that certain point (that threshold)?

Finally, does this mean that the water is now saturated with (or has excess of) hydrogen?
 
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  • #2
Mallignamius said:
I understand that when the oxygen molecules are heated up in a pot of water, they will vibrate increasingly as they get hotter. I guess that's what those little bubbles are at the bottom of the pot.
The bubbles are water vapour, not oxygen.

At some point, they will suddenly release. Is there a name for this threshold and a way to measure it? And am I correct in thinking that they are pushed up once they reach that certain point (that threshold)?
It is called boiling. It occurs when the vapour pressure of a liquid is equal to the ambient pressure.

Finally, does this mean that the water is now saturated with (or has excess of) hydrogen?
The water is not chemically altered by boiling. The bubbles release saturated water vapour. That is why a boiling kettle steams.

AM
 
  • #3
If only releasing the hydrogen from water was that easy, we'd have hydrogen cars on the roads already. ;)
 
  • #4
An interesting point to note however, is that when water is heated it becomes more acidic. This is due to the auto-dissociation of water (which can be attributed to the fact the water is amphoretic). Slightly off point but what the hey.:smile:
 
  • #5
Okay, thanks. Much appreciated.

But I don't understand how the vapor can linger on the bottom and suddenly release or pop up. I guess that point is the threshold I am trying to figure out. Any input, or better yet, a direction to point me to study further? I don't even know if this is chemistry or physics.

I also am curious why these bubbles are isolated. Why isn't this occurrence more evenly distributed? I mean, there is area on that surface where there aren't any bubbles. As I look into the pot, there are points where the bubbles form rapidly, creating a line of released bubbles.
 
  • #6
Mallignamius said:
Okay, thanks. Much appreciated.

But I don't understand how the vapor can linger on the bottom and suddenly release or pop up. I guess that point is the threshold I am trying to figure out.
The bubble of vapour is held in place by surface tension of water. Once the bubble gets large enough, its bouyancy will overcome this adhesion.

Mallignamius said:
I also am curious why these bubbles are isolated. Why isn't this occurrence more evenly distributed? I mean, there is area on that surface where there aren't any bubbles. As I look into the pot, there are points where the bubbles form rapidly, creating a line of released bubbles.
The bubbles cannot form just anywhere, they have to form at http://en.wikipedia.org/wiki/Nucleation" .
 
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FAQ: Boiling water - oscillation; when oxygen needs more room

1. What causes water to boil?

Water boils when its temperature reaches 100 degrees Celsius or 212 degrees Fahrenheit. This is the temperature at which the molecules in water have enough energy to overcome the attractive forces between them and transition from a liquid to a gas state.

2. How does boiling water create oscillation?

When water is heated, it begins to expand and the molecules move more rapidly. This creates an increase in pressure as the molecules collide with each other and the walls of the container. As the temperature continues to rise, the pressure eventually becomes too great and the water molecules escape as steam, causing an oscillating motion in the remaining water.

3. Why does oxygen need more room when water boils?

Oxygen is a gas that is dissolved in water. When water is heated and reaches its boiling point, the oxygen molecules gain more energy and escape as bubbles of gas. This causes the remaining water to become more dense and take up less space, creating a need for more room.

4. Can boiling water create a vacuum?

No, boiling water cannot create a vacuum. As the water boils and turns into gas, the steam exerts pressure on the surrounding environment. This pressure prevents a vacuum from being formed.

5. Is it safe to boil water in a closed container?

No, it is not safe to boil water in a closed container. As the water boils, the pressure inside the container increases, and if the container is not strong enough to withstand this pressure, it can explode. It is important to always boil water in open containers to avoid potential hazards.

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