What is Dalton's law?

Answer 1

I answered this on your Physics thread. ;)

Answer 2

Dalton Law Definition

Answer 3

In chemistry and physics, Dalton's law (also called Dalton's law of partial pressure) is related to the ideal gas laws. This empirical law was observed by John Dalton in 1801. It states that the total pressure exerted by a gaseous mixture is equal to the sum of the partial pressures of each individual component in a gas mixture.

Mathematically, the pressure P of a mixture of n gases can be defined as the summation

Ptotal = P1 + P2 + ... + Pn

where P1, P2, Pn represent the partial pressure of each component.

It is assumed that the gases do not react with each other.

Answer 4

"In chemistry and physics, Dalton's law (also called Dalton's law of partial pressure) is related to the ideal gas laws. This empirical law was observed by John Dalton in 1801. It states that the total pressure exerted by a gaseous mixture is equal to the sum of the partial pressures of each individual component in a gas mixture.

Mathematically, the pressure P of a mixture of n gases can be defined as the summation






where represent the partial pressure of each component.

It is assumed that the gases do not react with each other.

Combining Dalton Law with Boyle's and Avogadro's laws leads to the conclusion that a gas in an ideal gas mixture exerts a partial pressure whose ratio to total pressure equals its mole fraction.





where the mole fraction of the i-the component in the total mixture of m components


The relationship below provides a way to determine the volume based concentration of any individual gaseous component.





where: is the concentration of the ith component expressed in ppm.




Dalton's law is not exactly followed by real gases. Those deviations are considerably large at high pressures. In such conditions, the volume occupied by the molecules can become significant compared to the free space between them. Moreover, the short average distances between molecules raises the intensity of intermolecular forces between gas molecules enough to substantially change the pressure exerted by them. Neither of those effects are considered by the ideal gas model."

Answer 5

Dalton's Law of Partial Pressures
Concepts

One of the important predictions made by Avogadro is that the identity of a gas is unimportant in determining the P-V-T properties of the gas. This behavior means that a gas mixture behaves in exactly the same fashion as a pure gas. (Indeed, early scientists such as Robert Boyle studying the properties of gases performed their experiments using gas mixtures, most notably air, rather than pure gases.)

The ideal gas law,
P V = n R T ,

predicts how the pressure, volume, and temperature of a gas depend upon the number of moles of the gas. The number of moles, n, is the total moles of all of the gas-phase species.

Air, for example, is composed primarily of nitrogen and oxygen. In a given sample of air, the total number of moles is can be approximated as
n = nnitrogen + noxygen

This expression for n can be substituted into the ideal gas law to yield
P V = ( nnitrogen + noxygen ) R T

All molecules in the gas have access to the entire volume of the system, thus V is the same for both nitrogen and oxygen. Similarly, both compounds experience the same temperature. One can therefore split this expression of the ideal gas law into two terms, one for nitrogen and one for oxygen.
P = nnitrogen R T/V + noxygen R T/V

P = Pnitrogen + Poxygen

The above equation is called Dalton's Law of Partial Pressure, and it states that the pressure of a gas mixture is the sum of the partial pressures of the individual components of the gas mixture. Pnitrogen is the partial pressure of the nitrogen and Poxygen is the partial pressure of oxygen.
Pnitrogen = nnitrogen R T/V

Poxygen = noxygen R T/V

You'll notice that the equations for the partial pressures are really just the ideal gas law, but the moles of the individual component (nitrogen or oxygen) are used instead of the total moles. Conceptually Pnitrogen is the contribution nitrogen molecules make to the pressure and Poxygen is the contribution oxygen molecules make.

Answer 6

In chemistry and physics, Dalton's law (also called Dalton's law of partial pressure) is related to the ideal gas laws. This empirical law was observed by John Dalton in 1801. It states that the total pressure exerted by a gaseous mixture is equal to the sum of the partial pressures of each individual component in a gas mixture.

Mathematically, the pressure P of a mixture of n gases can be defined as the summation

where represent the partial pressure of each component.

It is assumed that the gases do not react with each other.

Combining Dalton Law with Boyle's and Avogadro's laws leads to the conclusion that a gas in an ideal gas mixture exerts a partial pressure whose ratio to total pressure equals its mole fraction.

where the mole fraction of the i-the component in the total mixture of m components

The relationship below provides a way to determine the volume based concentration of any individual gaseous component.

where: is the concentration of the ith component expressed in ppm.

Dalton's law is not exactly followed by real gases. Those deviations are considerably large at high pressures. In such conditions, the volume occupied by the molecules can become significant compared to the free space between them. Moreover, the short average distances between molecules raises the intensity of intermolecular forces between gas molecules enough to substantially change the pressure exerted by them. Neither of those effects are considered by the ideal gas model

Answer 7

In small talk The total pressure of gas mixture equals the sum of the partial

Answer 8

The total pressure of a gas mixture equals the sum of the partial pressures that make up the mixture