Anaes SAQs · Measurement & monitoring physics

The gas laws

Primary — Boyle (PV constant at constant T); Charles (V/T constant at constant P); Gay-Lussac (P/T constant at constant V); Avogadro (equal volumes = equal molecules; 1 mol = 22.4 L at STP); universal equation PV = nRT (R = 8.314 J/mol/K); Dalton (total P = sum of partial pressures, PO2 in air = 0.21 of total); Henry (dissolved gas proportional to partial pressure — uptake and decompression sickness); real gases — N2O critical temperature 36.5 C above room temp so it liquefies and its cylinder pressure is constant (gauge does NOT reflect contents, weigh it); O2 stays gaseous, pressure proportional to contents.