Whereas low-density ice forms a cubic crystal lattice, high-density ice forms a lattice named for this 2D shape. For 10 points each:
[10e] Name this polygon that names a unit cell that packs atoms at the highest possible density. Benzene’s ring forms this 2D shape.
ANSWER: regular hexagons [or hexagonal close packing]
[10m] One of these points occurs for the equilibrium between cubic and hexagonal ice around 1000 atmospheres and 200 Kelvin. On phase diagrams, these points occur at abrupt endpoints of line segments.
ANSWER: critical points
[10h] Thermodynamic critical points occur at a local maximum for this quantity. This quantity is the change in a system’s free energy when a molecule changes phases, so it must be equal for two phases in equilibrium.
ANSWER: chemical potential [prompt on mu; prompt on potential; prompt on partial molar Gibbs free energy or partial molar free energy; reject “potential energy” or “chemical potential energy”]
<Ethan Ashbrook, Science - Chemistry> ~20549~ <Editor: Adam Silverman>