What Is the Logic Behind Adding Pressure in the Derivation of PV=nRT?

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    Derivation Pv=nrt
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The discussion centers on the derivation of the ideal gas law, PV=nRT, particularly the role of pressure in this equation. It clarifies that pressure (P) is defined as force (F) per unit area (A), indicating uniform pressure across a surface. The reasoning behind summing pressures from small cubes is explained as calculating the total pressure exerted on the interior of the cube by individual particles, rather than simply aggregating pressures from the cubes themselves. This approach emphasizes that the pressure in one cube reflects the overall pressure in the container when particle velocities are consistent. Understanding this logic is crucial for grasping the derivation of the ideal gas law.
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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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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.
 

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