The equation P = $\frac{K}{V}$ illustrates

Analyze the question: The equation P = K/V relates pressure (P) and volume (V) with a constant K. We need to identify which gas law it describes.

Explain the concept: Boyle's law states that, for a fixed mass of gas at constant temperature, the volume of the gas is inversely proportional to its pressure.

Show the solution:

• Boyle's law: V ∝ 1/P, so V = K/P, which gives PV = K
• Rearranging: P = K/V

This matches the given equation exactly. Pressure and volume are inversely related, and temperature is held constant.

Checking the other options:

• Charles' law: V ∝ T at constant pressure, so V/T = K. It involves temperature, not an inverse P–V relationship.
• Dalton's law: The total pressure of a gas mixture equals the sum of the partial pressures of the individual gases (P_total = P₁ + P₂ + ...).
• Gay-Lussac's law: P ∝ T at constant volume, so P/T = K. It also involves temperature.

None of these has pressure inversely proportional to volume only, so only Boyle's law fits.

Answer: A. Boyle's law

Tip: Think "Boyle = Back-and-forth (inverse)". If P goes up, V goes down, and PV stays constant. If you see only P and V (no T) in an equation, it is almost always Boyle's law.