- #1
dRic2
Gold Member
- 883
- 225
Does anyone know a rigorous proof for Dalton's law ? I think I saw it once, but I can not find it again anywhere.
Thanks
Ric
Thanks
Ric
Because there is so little interaction of any type between the gas molecules that the forces from each can just be added together for a good approximation. So the pressures are added to get a total pressure.dRic2 said:Wikipedia only says the total pressure for a mixture of gases can be expressed as ##p_{tot} = \sum p_i##, but it doesn't say why.
Yes, but I remember that, for ideal gasses, it not an approximation. Maybe it just comes from the fact that ideal gasses are supposed to have no interaction between their molecules, but I remember my professor showed this with math... Maybe I remember wrong.FactChecker said:good approximation
I just said "good approximation" out of an over-abundance of caution. It's probably good enough to be called exact. Yes, the assumption of no interaction is key.dRic2 said:Yes, but I remember that, for ideal gasses, it not an approximation. Maybe it just comes from the fact that ideal gasses are supposed to have no interaction between their molecules, but I remember my professor showed this with math... Maybe I remember wrong.
A very noddy way of looking at the way pressures can add up would be to consider several small people banging against a wall with hammers. The effect of this (including the rate of hammering) is a pressure. Then take several larger people with bigger hammers, also banging on the wall. They will also have the effect of pressure and the two will just add together.FactChecker said:So the pressures are added to get a total pressure.
Dalton's law of partial pressure states that the total pressure of a mixture of gases is equal to the sum of the partial pressures of each individual gas in the mixture. In other words, the total pressure exerted by a mixture of gases is the same as the pressure each gas would exert if it were the only gas present in the container.
John Dalton was an English chemist and physicist who proposed the atomic theory of matter. He also conducted experiments on gases and discovered the law of partial pressures, which was later named after him in recognition of his contributions to the field of chemistry.
Dalton's law of partial pressure is used in various industries and applications, such as in scuba diving, where the partial pressure of oxygen and nitrogen in the air mixture is important for diver safety. It is also used in the production of industrial gases, such as oxygen and nitrogen, as well as in medical settings for administering anesthesia.
The mathematical formula for calculating partial pressure using Dalton's law is P = Ptotal * X, where P is the partial pressure of a gas, Ptotal is the total pressure of the gas mixture, and X is the mole fraction of the gas in the mixture.
Dalton's law of partial pressure is a specific application of the ideal gas law, which states that the pressure, volume, and temperature of a gas are related by the equation PV = nRT. In this equation, the partial pressure of a gas is represented by nRT/V, which is a result of Dalton's law.