1. The problem is to understand and use the ideal gas law formula: $$PV = nRT$$ where $P$ is pressure, $V$ is volume, $n$ is number of moles, $R$ is the ideal gas constant, and $T$ is temperature in Kelvin. 2. This formula relates the pressure, volume, temperature, and amount of an ideal gas. 3. Important rules: - Temperature must be in Kelvin. - $R$ is a constant, typically $0.0821$ L·atm/(mol·K) or $8.314$ J/(mol·K) depending on units. 4. To solve for any variable, rearrange the formula. For example, to find $P$, use $$P = \frac{nRT}{V}$$. 5. When rearranging, if dividing both sides by $V$, show cancellation: $$PV = nRT \implies \cancel{V}P = \frac{nRT}{\cancel{V}} \implies P = \frac{nRT}{V}$$ 6. This formula helps calculate one property of a gas if the others are known, assuming ideal behavior. Final answer: The ideal gas law is $$PV = nRT$$ and can be rearranged to solve for any variable as needed.