Applications of Ideal Gas Behavior
Ideal gas laws (PV = nRT) work well when gases are at low pressure and high temperature, where intermolecular forces are negligible.
- Calculating gas volumes in chemical reactions
- In industries, the amount of oxygen, hydrogen, or nitrogen needed for reactions is estimated using the ideal gas equation.
- Example: Determining how much hydrogen is needed to produce ammonia in the Haber process.
- Respiratory physiology
- Doctors use the ideal gas law to estimate how much oxygen is needed in ventilators or anesthesia delivery.
- Scuba diving tanks
- The gas inside tanks at room temperature behaves nearly ideally, so calculations for pressure and volume are straightforward.
- Aerosol sprays
- Propellant gases in deodorants or sprays expand ideally when released into the atmosphere.
Applications of Non-Ideal Gas Behavior
Non-ideal behavior appears at high pressures and low temperatures, where intermolecular forces and molecular sizes matter.
- Liquefied gases (LPG, LNG, oxygen, nitrogen)
- To convert gases into liquids, real gas behavior must be considered. The van der Waals equation is used to account for attractions and repulsions.
- Refrigeration and air conditioning
- Refrigerants (like Freon, ammonia, CO₂) deviate from ideal behavior when compressed and cooled. Engineers must use real gas equations to design efficient systems.
- Rocket propulsion
- Combustion gases inside rocket engines are at extremely high pressures and temperatures, so corrections to the ideal gas law are needed for accurate thrust calculations.
- Petrochemical industry
- Storage and transport of gases like methane, propane, or butane require real gas models, since these gases deviate significantly from ideal behavior at storage conditions.
- High-altitude science
- At very low pressures (like in the upper atmosphere), gases deviate from ideal assumptions, affecting weather balloon calculations and atmospheric modeling.
In simple words:
- Ideal gas law is used when gases behave “perfectly” (everyday calculations, low pressure, high temp).
- Non-ideal gas laws are needed in real engineering and industrial processes where gases are compressed, cooled, or liquefied.