ACS Organic Chemistry Practice Test

Boyle's law describes how pressure and volume of a gas are related when the amount of gas and the temperature are kept constant: their product remains constant. In other words, P1V1 = P2V2 expresses the same idea, showing the inverse relationship between pressure and volume as the gas is compressed or expanded at fixed n and T. This is not the same as the ideal gas law, which includes n and T (PV = nRT); it’s not Charles’s law, which relates volume to temperature; and it’s not a direct proportionality (P ∝ V), which would contradict the inverse relationship Boyle’s law states.