System, surroundings, and state functions
Chemical Thermodynamics · Chemistry
Molecule viewer
Interactive 3DBall-and-stick models with true bond angles — switch molecule to compare shapes.
Controls
Drag the sliders or type a value — the simulation updates live.
Study notes
Classify: (a) boiling water in an open beaker, (b) in a sealed cooker, (c) in a thermos. (a) Open beaker: water vapour escapes, heat enters → OPEN system (matter + energy cross). (b) Sealed cooker: no vapour escapes, but heat enters → CLOSED (energy only). (c) Thermos (ideal): no heat, no matter → ISOLATED. (d) The universe: the ultimate isolated system — nothing outside to exchange with.