Concept:The simple empirical gas laws (Boyle's, Charles's, and Gay-Lussac's laws) govern the behavior of gases within a closed system.
Solution:- A "closed system" strictly dictates that matter (gas) cannot enter or leave the container.
- Consequently, the mass of the gas—and therefore the number of moles (n)—remains permanently constant across all these foundational experiments.
- For example, Boyle's law requires constant \( T \) and \( n \); Charles's law requires constant \( P \) and \( n \). The number of moles is the universally constant variable across them all.
Why other options are incorrect:- Options A, B, & C: These variables are actively manipulated against each other. While one is held constant in a specific law (e.g., Temperature in Boyle's Law), they are not universally constant across all the basic gas laws like moles are.
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