I was wondering if Deuterium in water within a large vat would sink. A response said, "it depends on the kT." I don't understand. Could you explain it?
By deuterium, I assume you mean heavy water, i.e. deuterated water, D₂O? (Deuterium is an element. Pure deuterium would exist as a gas at normal conditions where water is a liquid.) Beyond that, perhaps you must be asking about ice cubes made from heavy water? (A single molecule of heavy water wouldn't sink or float in liquid water -- it would diffuse around.) Heavy water is denser than regular water (as the name implies). So an ice cube of D₂O would sink in a vat of liquid water. There is more information about the (somewhat weird) properties of deuterated compounds, and the PChem that explains them, in this video: th-cam.com/video/mbv-IQ1VnKs/w-d-xo.html
Thank you alot ❤️❤️❤️. in advance sorry if it is a ridiculus question. at 9:45 does it mean from 100 celsius to 450 (which if im right can be interpreted as the temprature of dissociation of hydrogen bonds because of that 6 kj/mol) will show a different properties than over 450? I mean may water will be vapour up to 450 and over that temp it can be named as a gas???
You're right that at 450 °C ≈ 720 K, the value of kT is about 6 kJ/mol. The hydrogen bonds don't all break suddenly at that temperature. Remember that some fraction ~exp(-E/kT) will be broken, according to the Boltzmann distribution (th-cam.com/video/-tMW8iU0_ts/w-d-xo.html). So many (but not all) of them will be broken at 450 °C. And a few (not as many) will be broken at lower temperatures. But it's correct that the liquid will begin to vaporize or boil at temperatures where enough hydrogen bonds break to allow the molecules to escape into the gas phase. A more detailed understanding of why the actual boiling point is 373 K = 100 °C also requires some discussion of the entropy of the liquid and gas phases. We can use the Gibbs free energy to combine energy and entropy and predict boiling points. See this video and the few that follow it: th-cam.com/video/1EBaMrymyNA/w-d-xo.html (PS - vapor and gas are the same. We usually just use vapor to describe the gas phase when there happens to be some liquid nearby.)
Concrete, clear, and to the point. Thank you very much!
8:40- would that be water vapour/gas?
I was wondering if Deuterium in water within a large vat would sink. A response said, "it depends on the kT." I don't understand. Could you explain it?
By deuterium, I assume you mean heavy water, i.e. deuterated water, D₂O? (Deuterium is an element. Pure deuterium would exist as a gas at normal conditions where water is a liquid.)
Beyond that, perhaps you must be asking about ice cubes made from heavy water? (A single molecule of heavy water wouldn't sink or float in liquid water -- it would diffuse around.) Heavy water is denser than regular water (as the name implies). So an ice cube of D₂O would sink in a vat of liquid water.
There is more information about the (somewhat weird) properties of deuterated compounds, and the PChem that explains them, in this video: th-cam.com/video/mbv-IQ1VnKs/w-d-xo.html
Thank you alot ❤️❤️❤️. in advance sorry if it is a ridiculus question. at 9:45 does it mean from 100 celsius to 450 (which if im right can be interpreted as the temprature of dissociation of hydrogen bonds because of that 6 kj/mol) will show a different properties than over 450? I mean may water will be vapour up to 450 and over that temp it can be named as a gas???
You're right that at 450 °C ≈ 720 K, the value of kT is about 6 kJ/mol.
The hydrogen bonds don't all break suddenly at that temperature. Remember that some fraction ~exp(-E/kT) will be broken, according to the Boltzmann distribution (th-cam.com/video/-tMW8iU0_ts/w-d-xo.html). So many (but not all) of them will be broken at 450 °C. And a few (not as many) will be broken at lower temperatures. But it's correct that the liquid will begin to vaporize or boil at temperatures where enough hydrogen bonds break to allow the molecules to escape into the gas phase.
A more detailed understanding of why the actual boiling point is 373 K = 100 °C also requires some discussion of the entropy of the liquid and gas phases. We can use the Gibbs free energy to combine energy and entropy and predict boiling points. See this video and the few that follow it: th-cam.com/video/1EBaMrymyNA/w-d-xo.html
(PS - vapor and gas are the same. We usually just use vapor to describe the gas phase when there happens to be some liquid nearby.)
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