Name: gas pressure patterns in kinetic molecular theory
Uploaded: 2020-09-03T13:38:27.000Z
Duration: 2 min 34 s
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Kinetic Molecular Theory and Gas Laws Explain Properties of Gas Molecules

Die Beobachtungen verschiedener Gaseigenschaften, wie sie in den verschiedenen abgeleiteten Gesetzen von Boyle, Charles, Gay-Lussac und Avogadro zum Ausdruck kommen stammen im Konzept von der kinetischen Gastheorie ab. Der von einem Gas ausgeübte Druck ergibt sich durch den Aufprall von sich ständig bewegenden Teilchen an den Wänden seines Behälters. Das Verringern des Behältervolumens bei konstanter Molzahl und Temperatur, bringt die Gasteilchen näher zusammen und verkleinert ihren Abstand.In diesem kleineren Volumen nimmt die Dichte des Gases und die Häufigkeit der Kollisionsfrequenz von Molekül und Wand zu. Daher steigt der Druck, den das Gas ausübt. Die umgekehrte Beziehung zwischen Druck und Volumen ist durch Boyles Gesetz beschrieben.Hinzufügen weiterer Gasmole in den Behälter bei konstanter Temperatur erhöht die Gasdichte, und damit die Kollisionsfrequenz. Um den anfänglichen Druck aufrechtzuerhalten, muss sich das Volumen ausdehnen. Diese direkte Beziehung zwischen Volumen und Molen ist durch das Avogadro-Gesetz beschrieben.Bedenken Sie nun, dass die Anzahl der Mole konstant gehalten und die Temperatur erhöht wird. Weil die durchschnittliche kinetische Energie von Gasteilchen mit der Temperatur proportional steigt, kollidieren die Teilchen häufiger und heftiger. Wenn das Volumen konstant gehalten wird, wird die Temperatur erhöht, die Dichte des Gases und die Kollisionsfrequenz steigt, und damit nimmt auch der Druck zu.Die direkte Beziehung zwischen Druck und Temperatur ist durch das Gesetz von Gay-Lussac beschrieben. Andererseits, wenn der Druck konstant bleibt, zusammen mit einer konstanten Molzahl, dann muss ein Temperaturanstieg mit einer Volumenvergrößerung zur Ausbreitung der Kollisionen über eine größere Fläche begleitet werden. Diese direkte Beziehung zwischen Volumen und Temperatur ist durch das Gesetz von Charles beschrieben.Schließlich, nach der kinetischen Gastheorie, werden Gasteilchen einander weder anziehen noch abstoßen. In einer Mischung aus verschiedenen Gasen wirken die Komponenten unabhängig und ihr individueller Druck bleibt von der Anwesenheit eines anderen Gases unberührt. Der Gesamtdruck der Mischung ist also die Summe der einzelnen Partialdrücke.Dies ist das Gesetz von Dalton.

kinetische molekültheorie und gasgesetze erklären eigenschaften von gasmolekülen

Der Test der kinetischen Molekulartheorie (KMT) und ihrer Postulate ist ihre Fähigkeit, das Verhalten eines Gases zu erklären und zu beschreiben. Die verschiedenen Gasgesetze (Boyle-, Charles-, Gay-Lussac-, Avogadro- und Dalton-Gesetze) können aus den Annahmen der KMT abgeleitet werden, die Chemiker zu der Annahme veranlasst haben, dass die Annahmen der Theorie die Eigenschaften von Gasmolekülen genau wiedergeben. <h4>Die kinetische Molekültheorie erklärt das Verhalten von Gasen</h4> Unter Hinweis darauf, dass der Gasdruck durch sich schnell bewegende Gasmoleküle ausgeübt wird und direkt von der Anzahl der Moleküle abhängt, die pro Zeiteinheit auf eine Flächeneinheit der Wand treffen, erklärt die KMT das Verhalten eines Gases konzeptionell wie folgt: <ul> <li>Gesetz von Gay-Lussac: Wenn die Temperatur erhöht wird, nehmen die durchschnittliche Geschwindigkeit und die kinetische Energie der Gasmoleküle zu. Bei konstant gehaltenem Volumen führt die erhöhte Geschwindigkeit der Gasmoleküle zu häufigeren und heftigeren Kollisionen mit den Behälterwänden und damit zu einem Anstieg des Drucks. Dies wird auch als Amontons-Gesetz bezeichnet.</li> <li>Charles’sches Gesetz: Wenn die Temperatur eines Gases erhöht wird, kann der Druck nur dann konstant gehalten werden, wenn das vom Gas eingenommene Volumen zunimmt. Dies führt zu größeren durchschnittlichen Distanzen, die die Moleküle zurücklegen, um die Behälterwände zu erreichen, sowie zu einer größeren Wandoberfläche. Diese Bedingungen werden sowohl die Häufigkeit von Molekül-Wand-Kollisionen als auch die Anzahl von Kollisionen pro Flächeneinheit verringern, wobei die kombinierten Effekte den Effekt erhöhter Kollisionskräfte aufgrund der größeren kinetischen Energie bei der höheren Temperatur ausgleichen.</li> <li>Boyles Gesetz: Wenn das Gasvolumen verringert wird, nimmt die Behälterwandfläche ab und die Kollisionsfrequenz zwischen Molekül und Wand nimmt zu, was beides den vom Gas ausgeübten Druck erhöht.</li> <li>Avogadros Gesetz: Bei konstantem Druck und konstanter Temperatur sind Häufigkeit und Kraft der Molekül-Wand-Kollisionen konstant. Unter solchen Bedingungen erfordert eine Erhöhung der Anzahl gasförmiger Moleküle eine proportionale Vergrößerung des Behältervolumens, um eine Verringerung der Anzahl von Kollisionen pro Flächeneinheit zu erreichen und so die erhöhte Kollisionshäufigkeit auszugleichen.</li> <li>Daltons Gesetz: Aufgrund der großen Abstände zwischen ihnen bombardieren die Moleküle eines Gases in einer Mischung die Behälterwände mit der gleichen Frequenz, unabhängig davon, ob andere Gase vorhanden sind oder nicht, und der Gesamtdruck einer Gasmischung entspricht der Summe der (Partialdrücke der einzelnen Gase.</li> </ul> Dieser Text wurde angepasst von <a href="https://openstax.org/books/chemistry-2e/pages/9-5-the-kinetic-molecular-theory">Openstax, Chemistry 2e, Section 9.5: The Kinetic-Molecular Theory.</a>

Kinetische Molekültheorie und Gasgesetze erklären Eigenschaften von Gasmolekülen

Der Test der kinetischen Molekültheorie (KMT) und ihrer Postulate ist ihre Fähigkeit, das Verhalten eines Gases zu erklären und zu beschreiben. Die verschiedenen Gasgesetze ...

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gas pressure patterns in kinetic molecular theory

Kinetic molecular theory explains gas pressure by linking it to the motion of gas molecules. Gas pressure comes from rapidly moving molecules hitting the walls of a container. It depends on how many molecules strike a unit area in a given time.

The theory also helps explain the main gas laws. In Gay-Lussac’s law, also called Amontons’s law, raising temperature increases the average speed and kinetic energy of gas molecules. If volume stays constant, the molecules collide with the walls more often and more forcefully, so pressure increases.

Charles’s law shows what happens when temperature rises at constant pressure. The gas must expand to keep pressure steady. That larger volume means molecules travel farther before reaching the walls, and the wall area increases too. These changes lower collision frequency and the number of collisions per unit area, which balances the stronger collisions caused by the higher kinetic energy.

Boyle’s law describes the effect of smaller volume. When gas volume decreases, the container wall area also decreases. Molecule-wall collisions become more frequent, and the pressure rises. Avogadro’s law says that at constant pressure and temperature, the collision rate and collision force stay constant. If the number of gas molecules increases, the volume must increase in proportion so the collisions per unit area can drop enough to offset the added molecules.

Dalton’s law applies to gas mixtures. Because gas molecules are far apart, one gas in a mixture strikes the container walls with the same frequency whether other gases are present or not. The total pressure of the mixture equals the sum of the partial pressures of the individual gases. These gas laws show how the assumptions of kinetic molecular theory fit the behavior of gases.

Gas Pressure Patterns in Kinetic Molecular Theory

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definition and measurement of pressure: atmospheric pressure, barometer, and manometer

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Pressure Units and Tools for Gas Measurement

Pressure is the force applied to a given area, and gas pressure comes from gas molecules colliding with surfaces. Each collision is tiny, but many collisions over a small area can create high pressure. Pressure increases when force increases or when the area gets smaller. It decreases when force drops or when the area gets larger. Pressure is measured in pascals, or Pa, in the SI system. One pascal equals 1 newton per square meter, and a newton is a unit of force equal to 1 kg·m/s2. A pascal...

gas laws: boyle's, gay-lussac, charles', avogadro's, and ideal gas law

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How Gas Pressure, Volume, and Temperature Change

Gas pressure, volume, temperature, and amount are linked by several gas laws. Scientists found these relationships by studying how a confined gas changes when one variable is held constant and another changes. These patterns apply to an ideal gas, which is a useful model for gases under low pressure and high temperature. Gay-Lussac’s law, also called Amontons’s law, connects pressure and temperature. If gas is trapped in a rigid container, the volume and number of moles stay constant. When the...

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Ideal Gas Law at STP and Gas Density

The ideal gas law links pressure, volume, number of moles, and temperature. It helps explain how gas volume changes when pressure or temperature changes. At standard temperature and pressure, or STP, the values are 273.15 K and 1 atm. At STP, one mole of an ideal gas occupies about 22.4 L. This is called the standard molar volume. The gas can be hydrogen, oxygen, argon, or carbon dioxide, and the volume is still about 22.4 liters. Half a mole occupies 11.2 L, and 2 moles occupy 44.8 L. The...

mixtures of gases: dalton's law of partial pressures and mole fractions

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Gas Pressure in Mixtures: Partial Pressures

Gas pressure in mixtures is described by partial pressure and mole fraction. When gases do not chemically react, each gas in the mixture acts as if it were alone in the container. The pressure from one gas is called its partial pressure. For a mixture of three gases, A, B, and C, the total pressure equals the sum of their partial pressures: PA, PB, and PC. This is Dalton's law of partial pressures. It states that the total pressure of a mixture of ideal gases is the sum of the pressures from...

chemical stoichiometry and gases: using ideal gas law to determine moles

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Stoichiometry of Gases with the Ideal Gas Law

Chemical stoichiometry links the amounts of reactants and products in a chemical reaction. For gases, those amounts can also be measured by volume. If a gas’s volume, pressure, and temperature are known, the ideal gas equation can be used to find the number of moles present. The same idea works in reverse. If the moles of a gas are known, its volume can be found at any temperature and pressure. The transcript gives an example using 8.88 g of gallium reacting with excess hydrochloric acid.

basic postulates of kinetic molecular theory: particle size, energy, and collision

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Kinetic Molecular Theory and Gas Behavior

Kinetic molecular theory explains gas behavior at the particle level. It gives a microscopic model for what happens when pressure or temperature changes. Gas laws describe how macroscopic properties change, but they do not explain why those changes happen. The theory was put into a complete form by Rudolf Clausius in 1857. It was built from hundreds of experimental observations about gases. Those observations helped explain the different gas laws through a few basic postulates. One key idea...

kinetic molecular theory and gas laws explain properties of gas molecules

Kinetic molecular theory explains gas pressure by linking it to the motion of gas molecules. Gas pressure comes from rapidly moving molecules hitting the walls of a container. It depends on how many molecules strike a unit area in a given time. The theory also helps explain the main gas laws. In Gay-Lussac’s law, also called Amontons’s law, raising temperature increases the average speed and kinetic energy of gas molecules. If volume stays constant, the molecules collide with the walls more...

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Gas Particle Speed Distributions and Temperature

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real gases: effects of intermolecular forces and molecular volume deriving van der waals equation

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Real Gases: When the Ideal Gas Law Breaks Down

Real gases are gases that do not always follow the ideal gas law, PV = nRT, especially when pressure is high or temperature is low. The ideal gas model assumes gas particles have no attractive or repulsive forces and take up negligible space compared with the container. At room temperature and 1 atm or less, many gases behave close to ideally. When conditions change, the measured relationships between pressure, volume, and temperature can drift away from the ideal prediction. One way to see...

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Explore how kinetic molecular theory explains gas pressure, temperature, volume changes, and the gas laws of Boyle, Charles, Gay-Lussac, Avogadro, and Dalton.

Gas Pressure Patterns in Kinetic Molecular Theory | JoVE K12

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Understand the relationship among pressure, temperature, volume, and phase.

Gas Pressure Patterns in Kinetic Molecular Theory

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