Repeated ideal-stage enrichment 2026-10-18
Stipulate a constant relative volatility . The vapor-liquid equilibrium model then becomesAn initial liquid mole fraction gives an equilibrium vapor mole fraction . Now imagine completely condensing a small sample of that vapor and using this condensate as a fresh liquid for another equilibration. Repeating this formal operation givesThese are original model calculations of ideal-stage enrichment. They are not measured compositions, a reflux design, or successive compositions of one pot undergoing simple distillation. That pot loses the more volatile component and becomes depleted; each step here instead starts from the previous enriched condensate. The displayed sequence specifies compositions, not the recoverable amount at each step.
Simple distillation 2026-10-18
In simple distillation, pot vapor passes directly to the laboratory condenser. An initial small condensate sample can approximate vapor-liquid equilibrium with the current pot liquid. Removing enriched distillate depletes the pot's more volatile component. A collected fraction averages the changing condensate composition, rather than preserving the first-drop mole fraction.[ref]
Distillation introduction. Chem2O06 Laboratory Manual by McMaster University; A Mixture of Ideal Liquids, discussion of first and later fractions
Superheated liquid 2026-10-18
A liquid maintained above its equilibrium boiling temperature at the imposed pressure. A barrier to nucleation can delay its conversion into vapor, making this a metastable state.
Supersaturated vapor 2026-10-18
A vapor whose partial pressure exceeds its vapor pressure at the local temperature; nucleation can permit condensation.
Wilson cloud-chamber experiment 2026-10-18
Charles Thomson Rees Wilson's 1927 lecture recalls Electron cloud trails produced with X-rays in 1911, then alpha particle trails from a radium-tipped source. The improved 1912 chamber had a wide, shallow space with a suddenly falling floor to limit stirring. A roof–floor clearing electric field removed unwanted ions. Sharp photography required expansion, then the ionizing particle, then illumination.[ref]
On the Cloud Method of Making Visible Ions and the Tracks of Ionizing Particles by Charles Thomson Rees Wilson. Nobel Lectures, Physics 1922–1941; Wilson, 1927 Nobel lecture, pp.199–201, Fig.3: apparatus and operating sequence
The piston mechanism connects the space beneath the moving floor to an evacuated vessel: opening the valve lets the floor drop. Water in a trough supplies the vapor. The Smithsonian's surviving demonstration object is explicitly a 1961 replica of the 1912 apparatus.[ref]
Wilson’s Cloud Chamber, Replica of Cavendish Lab Apparatus by Smithsonian Institution. Smithsonian Institution, Wilson's cloud chamber, replica of Cavendish Lab apparatus, object nmah_700205, “History and basic principle” and “Date made”
After dust removal, X-rays increased droplet formation above a lower expansion threshold; larger expansions also produced dense background cloud.[ref]
On the Cloud Method of Making Visible Ions and the Tracks of Ionizing Particles by Charles Thomson Rees Wilson. Nobel Lectures, Physics 1922–1941; Wilson, 1927 Nobel lecture, pp.194–197: cloud limits and clearing controls

