Ideal Gas Law:A fundamental equation describing the behavior of an ideal gas: $PV = nRT$, where $P$ is pressure, $V$ is volume, $n$ is moles of gas, $R$ is the universal gas constant, and $T$ is temperature.
Charles' Law:States that the volume of a gas is directly proportional to its temperature when pressure and the number of moles are held constant: $\frac{V}{T} = k$.
Brønsted-Lowry Acid-Base Theory: Defines acids as proton donors and bases as proton acceptors. This theory broadens the concept of acid-base reactions beyond aqueous solutions.