Name: gas mixtures and their partial pressures
Uploaded: 2023-09-18T17:11:17.000Z
Duration: 1 min 11 s
Channel: JoVE

Stellen Sie sich ein Gas in einem Behälter vor. Der vom Gas ausgeübte Druck ist die Summe der Kräfte, die aufgrund der molekularen Kollisionen zwischen seinen Molekülen und der umgebenden Oberfläche ausgeübt werden.
Ein Gas mit vielen Molekülen übt einen höheren Druck aus als ein Gas mit einer geringeren Anzahl von Molekülen im selben Behälter. Der Druck von der einzelnen Komponente wird also als Partialdruck bezeichnet.
Stellen Sie sich eine Mischung idealer Gase in einem Behälter im thermischen Gleichgewicht vor. Der Gesamtdruck im Inneren des Behälters entspricht der Summe der Partialdrücke seiner Komponenten. Diese Beobachtung ist als Daltonsches Gesetz des Partialdrucks bekannt.
Ruft man die ideale Gasgleichung hervor und setzt man die Partialdrücke der einzelnen Gase ein, so kann der Gesamtdruck bestimmt werden.
Der Partialdruck eines Dampfes, der sich im Gleichgewicht mit der flüssigen Phase desselben Stoffes befindet, wird als Dampfdruck bezeichnet.
Das Verhältnis des Partialdrucks von Wasserdampf zum Dampfdruck von Wasser bei einer Temperatur wird als relative Luftfeuchtigkeit bezeichnet.

<ol>
	<li>OpenStax. (2019). Universitätsphysik Vol. 2. [Web-Version], Seite 37 - 38. Abgerufen von <a href="https://openstax.org/books/university-physics-volume-2/pages/2-2-pressure-temperature-and-rms-speed">https://openstax.org/books/university-physics-volume-2/pages/2-2-pressure-temperature-and-rms-speed</a></li>
</ol>

das dalton'sche gesetz der partialdrücke

Dalton's Law of Partial Pressure

Der Partialdruck eines Gases ist ein Maß für die thermodynamische Aktivität der Moleküle des Gases. Der Druck, den ein Gas erzeugen würde, wenn es das gesamte verfügbare Volumen einnehmen würde, wird als der Partialdruck des Gases bezeichnet. Wenn zwei oder mehr Gase in einem Behälter gemischt werden, bewegen sich die Moleküle zufällig und kollidieren miteinander, wodurch sie ein thermisches Gleichgewicht erreichen. Wenn die Gase die gleiche Temperatur haben, haben ihre Moleküle die gleiche durchschnittliche kinetische Energie. Jedes Gas gehorcht daher dem idealen Gasgesetz separat und übt einzeln den gleichen Druck auf die Wände eines Behälters aus. Daher ist in einer Mischung von Gasen der Gesamtdruck im Behälter die Summe der Partialdrücke der einzelnen Gaskomponenten, vorausgesetzt, dass das ideale Gasverhalten und keine chemischen Reaktionen zwischen den Komponenten vorliegen. Dieses Gesetz ist als Dalton'sches Gesetz der Partialdrücke bekannt. Die Theorie wurde vom englischen Wissenschaftler John Dalton (1766–1844) formuliert. Das Daltonsche Gesetz steht im Einklang mit der Tatsache, dass sich die Drücke nach dem Pascalschen Prinzip addieren. In einer Mischung idealer Gase im thermischen Gleichgewicht ist die Anzahl der Moleküle jedes Gases proportional zu ihrem Partialdruck.

Eine weitere wichtige Anwendung des Partialdrucks ist der Dampfdruck, der der Partialdruck eines Dampfes ist, bei dem er im Gleichgewicht mit der Flüssigkeitsphase derselben Substanz steht. Bei keiner Temperatur kann der Partialdruck des Wassers in der Luft den Dampfdruck des Wassers bei dieser Temperatur übersteigen, denn sobald der Partialdruck den Dampfdruck erreicht, kondensiert das Wasser aus der Luft. Tau ist ein Beispiel für diese Kondensation. Die Temperatur, bei der in einer Luftprobe Kondensation auftritt, wird als Taupunkt bezeichnet. Er lässt sich leicht messen, indem man eine Metallkugel langsam abkühlt; der Taupunkt ist die Temperatur, bei der die Kondensation auf der Kugel erstmals auftritt.

Das Dalton'sche Gesetz der Partialdrücke

Der Partialdruck eines Gases ist ein Maß für die thermodynamische Aktivität der Moleküle des Gases. Der Druck, den ein Gas erzeugen würde, wenn es ...

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gas mixtures and their partial pressures

Gas mixtures have a total pressure that comes from the partial pressures of each gas. A partial pressure is the pressure one gas would make if it filled the whole container by itself. This idea helps explain how gases behave when they are mixed together.

When two or more gases share a container, their molecules move randomly and collide with one another. If the gases are at the same temperature, they reach thermal equilibrium. Their molecules then have the same average kinetic energy. In that case, each gas follows the ideal gas law separately and pushes on the walls of the container on its own.

The total pressure in the container is the sum of the partial pressures of the component gases. This result is called Dalton's law of partial pressures. It applies when the gases behave like ideal gases and do not react chemically with one another. The law was developed by the English scientist John Dalton, who lived from 1766 to 1844. It also agrees with Pascal's principle, which says that pressures add up.

Partial pressure also helps describe vapor pressure. Vapor pressure is the partial pressure of a vapor when it is in equilibrium with the liquid form of the same substance. In air, the partial pressure of water cannot rise above the vapor pressure of water at that temperature. If it reaches that value, water condenses out of the air. Dew is one common example of this process.

The temperature where condensation begins in a sample of air is called the dew point. One simple way to measure it is to cool a metal ball slowly. The dew point is the temperature at which condensation first appears on the ball.

Gas Mixtures and Their Partial Pressures

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Gas Mixtures and Their Partial Pressures | JoVE K12

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Gas Mixtures and Their Partial Pressures

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