An extensively scaffolded review worksheet for gas stoichiometry. Features a "Tactical Toolbox" cheat sheet, "Pre-Mission Checks" for molar masses, and a highly structured multi-phase breakdown for complex Ideal Gas Law problems. Includes 9 representative problems from the provided source PDF with explicit templates for Volume-to-Volume shortcuts, railroad-track mass-to-volume STP problems, and multi-step non-STP missions.