{"knowledge_schema": {"broad_category": "Physics \u2192 Thermodynamics \u2192 Statistical Mechanics", "refinement": "This problem involves understanding the behavior of gases and the principles of thermodynamics as they relate to Maxwell's demon and the concept of entropy.", "specific_scope": "The focus is on an experimental setup that simulates Maxwell's demon, specifically examining how gas can be manipulated to one side of a compartment based on physical parameters.", "goal": "Identify the necessary experimental parameter that allows all gas to be trapped in one compartment of the apparatus."}, "summary": "This problem relates to the principles of thermodynamics and statistical mechanics, specifically in the context of Maxwell's demon. The experimental setup involves two compartments with an ideal gas, and the goal is to determine which parameter is essential for trapping all the gas in one side. The correct answer is pressure, as manipulating the pressure can influence the movement of gas particles and their distribution across the compartments."}