The Ideal Gas Law: PV=nRT in Real Life
Published Apr 13, 2026 · 6 min read
PV = nRT relates pressure (P), volume (V), moles of gas (n), the gas constant (R), and temperature (T). It predicts gas behavior in countless real situations.
The Variables
| Variable | Unit | Meaning |
|---|---|---|
| P | atm or kPa | Pressure |
| V | Liters | Volume |
| n | moles | Amount of gas |
| R | 0.0821 L·atm/mol·K | Gas constant |
| T | Kelvin | Temperature (°C + 273.15) |
Real-Life Applications
- Tire pressure — Tires gain ~1 PSI per 10°F temperature increase
- Scuba diving — Air volume halves every 10m depth (Boyle's Law, a special case)
- Cooking at altitude — Lower atmospheric pressure means water boils below 100°C
- Airbags — Sodium azide decomposes, producing N₂ gas to inflate the bag in milliseconds
Try it: Use our Ideal Gas Law Calculator to solve for any variable in PV = nRT.