The General Gas Law and Ideal Gas Mixtures

Combining Boyle's Law (V ∝ 1/P), Charles's Law (V ∝ T), and Avogadro's Law (V ∝ n) produces the universal Ideal Gas Equation:

P V = n R T = (m / M) R T.

Where n is number of moles, m is gas mass, M is molar mass, and R is the Universal Gas Constant (8.314 J/(mol.K) or 0.0821 L.atm/(mol.K)).

The General Gas Law for a constant mass of gas undergoing thermodynamic transitions:

(P1 × V1) / T1 = (P2 × V2) / T2.

Gas Mixtures in Interconnected Vessels: When a valve between two gas reservoirs (P1, V1 and P2, V2) is opened at constant temperature, the total number of moles is conserved. Applying Boyle's Law yields: P_mixture × V_total = (P1 × V1) + (P2 × V2), where V_total = V1 + V2.