Derivation of PV=nRT: Exploring Logic Behind the Ideal Gas Law

In summary, the conversation discusses the derivation of the PV=nRT equation for ideal gas. The interlocutors mention that pressure is equal to force divided by area and is consistent throughout the surface. They also question the reasoning behind adding up the pressure of small cubes and explain that it is actually the pressure exerted on the cube's interior per particle that is being added.
  • #1
kidsasd987
143
4
http://quantumfreak.com/derivation-of-pvnrt-the-equation-of-ideal-gas/please check eq.(7)

pressure equation is P=F/A which means, in any region over the surface, pressure will be the same.
for example, if we assume all the particles have the same mean squared velocity, pressure of one cube will be the same as the pressure of the whole container.

I wonder why we add up all the pressure we found for the small cubes, and what's the logic behind it?
 
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  • #2
You're not adding up the pressure of small cubes, you're adding up the pressure exerted on the cube's interior per particle to get the total pressure.
 

What is the ideal gas law?

The ideal gas law, also known as the general gas equation, is a fundamental equation in thermodynamics that relates the pressure, volume, temperature, and number of moles of an ideal gas. It is expressed as PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature.

How is PV=nRT derived?

PV=nRT is derived from a combination of the Boyle's law, Charles's law, and Avogadro's law. Boyle's law states that at a constant temperature, the product of pressure and volume of an ideal gas is a constant. Charles's law states that at a constant pressure, the volume of a gas is directly proportional to its temperature. And Avogadro's law states that at a constant temperature and pressure, the volume of an ideal gas is directly proportional to the number of moles. By combining these laws, we can derive the ideal gas law equation.

What are the assumptions behind the ideal gas law?

The ideal gas law assumes that the gas particles have negligible volume and do not interact with each other. It also assumes that the gas particles are in constant, random motion and that there are no external forces acting on the gas. Additionally, the ideal gas law assumes that the temperature is in Kelvin and the pressure is in atmospheres.

What is the significance of the ideal gas law?

The ideal gas law is significant because it allows us to predict the behavior of ideal gases under different conditions. It is used in various fields of science and engineering, such as chemistry, physics, and thermodynamics, to calculate the properties of gases and to design and analyze gas-based systems.

Are there any limitations to the ideal gas law?

Yes, there are limitations to the ideal gas law. It does not accurately describe the behavior of real gases at high pressures and low temperatures. This is because at these conditions, the gas particles are no longer ideal, and they start to interact with each other. Additionally, the ideal gas law does not take into account the molecular size and shape of the gas particles, which can also affect their behavior.

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