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

Weźmy pod uwagę gaz wewnątrz pojemnika. Ciśnienie wywierane przez gaz jest sumą sił wywieranych w wyniku zderzeń molekularnych między jego cząsteczkami a otaczającą powierzchnią.
Gaz z wieloma cząsteczkami wywiera wyższe ciśnienie niż gaz z mniejszą liczbą cząsteczek w tym samym pojemniku. Tak więc ciśnienie od pojedynczego elementu nazywa się jego ciśnieniem cząstkowym.
Rozważmy mieszaninę gazów doskonałych w pojemniku w równowadze termicznej. Całkowite ciśnienie wewnątrz zbiornika jest równe sumie ciśnień cząstkowych jego składników. Ta obserwacja jest znana jako prawo ciśnień cząstkowych Daltona.
Przywołując równanie gazu doskonałego i podstawiając ciśnienia cząstkowe poszczególnych gazów, można określić ciśnienie całkowite.
Ciśnienie parcjalne pary, która jest w równowadze z fazą ciekłą tej samej substancji, nazywa się prężnością pary.
Stosunek ciśnienia parcjalnego pary wodnej do ciśnienia pary wodnej w temperaturze jest znany jako wilgotność względna.

<ol>
	<li>Protokół OpenStax. (2019). Fizyka uniwersytecka Vol. 2. [Wersja internetowa], str. 37 - 38. Pobrane z <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>

prawo daltona dotyczące ciśnienia cząstkowego

Dalton's Law of Partial Pressure

Ciśnienie cząstkowe gazu jest miarą aktywności termodynamicznej cząsteczek gazu. Ciśnienie, jakie wytworzyłby gaz, gdyby zajmował całą dostępną objętość, nazywa się ciśnieniem cząstkowym gazu. Jeśli dwa lub więcej gazów zmiesza się razem w pojemniku, cząsteczki poruszają się losowo i zderzają się ze sobą, powodując osiągnięcie równowagi termicznej. Gdy gazy mają tę samą temperaturę, ich cząsteczki mają tę samą średnią energię kinetyczną. Zatem każdy gaz oddzielnie podlega prawu gazu doskonałego i indywidualnie wywiera takie samo ciśnienie na ścianki pojemnika. Dlatego w mieszaninie gazów całkowite ciśnienie w pojemniku jest sumą ciśnień cząstkowych gazów składowych, przy założeniu zachowania gazu doskonałego i braku reakcji chemicznych między składnikami. Prawo to znane jest jako prawo Daltona dotyczące ciśnień cząstkowych. Teorię stworzył angielski naukowiec John Dalton (1766–1844). Prawo Daltona jest zgodne z faktem, że ciśnienia sumują się, zgodnie z zasadą Pascala. W mieszaninie gazów doskonałych znajdujących się w równowadze termicznej liczba cząsteczek każdego gazu jest proporcjonalna do jego ciśnienia cząstkowego.

Innym ważnym zastosowaniem ciśnienia cząstkowego jest ciśnienie parcjalne, czyli ciśnienie cząstkowe pary, przy którym znajduje się ona w równowadze z fazą ciekłą tej samej substancji. W dowolnej temperaturze ciśnienie cząstkowe wody w powietrzu nie może przekroczyć ciśnienia pary wodnej w tej temperaturze, ponieważ ilekroć ciśnienie cząstkowe osiąga ciśnienie pary, woda skrapla się z powietrza. Rosa jest przykładem tej kondensacji. Temperatura, w której następuje kondensacja próbki powietrza, nazywana jest punktem rosy. Można go łatwo zmierzyć, powoli schładzając metalową kulkę; punkt rosy to temperatura, w której na kuli po raz pierwszy pojawia się kondensacja.

Prawo Daltona dotyczące ciśnienia cząstkowego

Ciśnienie parcjalne gazu jest miarą aktywności termodynamicznej cząsteczek gazu. Ciśnienie, które wytworzyłby gaz, gdyby zajmował ...

Education

JoVE Core

Physics

Fizyka

Unit 1

Jednostka 1

The Kinetic Theory of Gases

Kinetyczna teoria gazów

KEY TERMS AND CONCEPTS

Kluczowe terminy i pojęcia

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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key terms and concepts

Learn how gas mixtures share pressure through partial pressures, how Dalton's law works, and how vapor pressure and dew point explain condensation in air.

Gas Mixtures and Their Partial Pressures | JoVE K12

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Gas Mixtures and Their Partial Pressures

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