Antifreeze in vehicles: Ethylene glycol dissolved in water depresses the freezing point ($\Delta Tf$ = iKfm). A 50% w/v solution lowers the freeze point to ≈ −37°C, preventing engine block cracking in winter.

Salting icy roads: NaCl and $CaCl_{2}$ are spread on roads to depress the freezing point of ice-water mix. $CaCl_{2}$ (i=3) is more effective than NaCl (i=2) per mole because it produces more particles.

Carbonated beverages (Henry's Law): Beverages are bottled under ~3.5 atm $CO_{2}$ pressure. On opening, pressure drops to 1 atm → $CO_{2}$ solubility decreases → gas escapes as bubbles. Warm drinks go flat faster because K_H increases with temperature, reducing solubility.

Decompression sickness — "The bends" (Henry's Law): At depth, high pressure dissolves $N_{2}$ in blood (x = p/K_H). Rapid ascent lowers pressure suddenly → $N_{2}$ comes out of solution as bubbles in tissues and joints → severe pain, paralysis, or death. Prevention: slow ascent, breathing helium-oxygen mixtures (He has lower K_H than $N_{2}$).

Reverse osmosis — water purification: Applying pressure > osmotic pressure to seawater (π ≈ 27 atm) through a semipermeable membrane forces pure water out, leaving salt behind. Used in desalination plants and home RO filters.

Intravenous fluids and blood compatibility: Blood plasma osmotic pressure ≈ 7.7 atm at 37°C. IV fluids (0.9% NaCl, 5% glucose) are isotonic — equal osmotic pressure prevents haemolysis or crenation. In hypertonic saline, cells lose water (crenation, shrinkage). In hypotonic solution, water enters cells (haemolysis, bursting).

Food preservation (pickling and jam): High concentrations of salt or sugar create hypertonic environments. Bacterial cells lose water osmotically → dehydrate → cannot reproduce. This is the basis of salt-curing, pickling in brine, and jam making.

Dialysis for kidney failure: Waste products (urea, creatinine) diffuse through a semipermeable dialysis membrane from blood (higher concentration) to isotonic dialysis fluid. Water is not lost because the fluid is osmotically matched to blood.

Molar mass of biomolecules: Osmotic pressure is used to determine molar masses of proteins and polymers because π is measurable even for 10^{-4} M solutions of very large molecules, while $\Delta Tb$ and $\Delta Tf$ would be < 0.001 K (unmeasurable).

Camphor Rast method: The extremely high Kf of camphor (40 K·kg/mol) produces large, measurable $\Delta Tf$ values for tiny amounts of solute — enabling molar mass determination of organic compounds.