"At constant temperature, the volume of a given quantity of any gas is inversely proportional to pressure." This law is called:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Boyle's law
Boyle’s law (1662) states that at constant temperature, the volume of a fixed amount of gas is inversely proportional to its pressure: \(V\propto\frac{1}{P}\), or \(PV=\) constant. Doubling the pressure halves the volume.
Why the other options are incorrect
Option (1) Gas law — Incorrect. “Gas laws” is the general name for all the laws of gases (Boyle’s, Charles’s, Avogadro’s and others), not one law.
Option (3) Charles's law — Incorrect. At constant pressure, the volume of a gas is proportional to its absolute temperature.
Option (4) Gas equation — Incorrect. \(PV=nRT\) combines all the gas laws; it is not the single relation between pressure and volume.