Which variable is held constant when applying Boyle's Law?

In the context of Boyle's Law, the key variable that is held constant is temperature. Boyle's Law describes the relationship between the pressure and volume of a gas when the temperature is held constant. The law states that the pressure of a gas is inversely proportional to its volume when the number of moles of gas is also constant and temperature remains unchanged. In practical terms, if the volume of a gas decreases, its pressure increases, provided the temperature does not fluctuate during the process.

This means that for Boyle's Law calculations, conditions must be kept consistent across the experiment to ensure that any changes to pressure and volume can be attributed directly to their relationship without the influence of temperature changes skewing the results. Therefore, identifying temperature as the variable that remains constant is essential to applying Boyle's Law correctly in various scenarios involving gases.