$word_{count}$: 210

PV = nRT. R = 0.0821 L.$\frac{atm}{mol.K}$ = 8.314 $\frac{J}{mol.K}$. Kinetic theory assumptions: point particles, no forces, elastic collisions, KE proportional to T. Average KE = $\frac{3}{2}$kT per molecule = $\frac{3}{2}$RT per mole. KE depends only on T, not on gas identity. Three speeds: $u_{mp}$ = sqrt$\frac{2RT}{M}$, $u_{avg}$ = sqrt$\frac{8RT}{piM}$, $u_{rms}$ = sqrt$\frac{3RT}{M}$. Ratio: 1 : 1.128 : 1.224. All proportional to sqrt$\frac{T}{M}$. Maxwell-Boltzmann distribution: bell-shaped curve plotting fraction of molecules vs speed. Peak at $u_{mp}$. Higher T: peak shifts right, flattens (broader). Higher M: peak shifts left (slower). Area under curve always = 1 (total probability). Graham's law: r1/r2 = sqrt$\frac{M2}{M1}$. Dalton's law: $P_{total}$ = sum($P_i$). Mean free path: average distance between collisions = $\frac{kT}{sqrt(2}$ pi $d^2$ P). Increases with T, decreases with P and molecular size.