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Gas law calculators solve Boyle's, Charles's, Gay-Lussac's, and the combined gas law for pressure, volume, and temperature relationships of ideal gases.

Formule

PV = nRT (ideal gas law); P₁V₁/T₁ = P₂V₂/T₂ (combined gas law)
P
Pressure (atm/Pa)
V
Volume (litres/m³)
n
Moles of gas (mol)
R
Gas constant (0.0821 L·atm/(mol·K))
T
Temperature (Kelvin)

Guide étape par étape

  1. 1Boyle's law: P₁V₁ = P₂V₂ (constant T)
  2. 2Charles's law: V₁/T₁ = V₂/T₂ (constant P)
  3. 3Gay-Lussac's: P₁/T₁ = P₂/T₂ (constant V)
  4. 4Combined: P₁V₁/T₁ = P₂V₂/T₂

Exemples résolus

Entrée
Boyle's: V₁=4L, P₁=2atm, P₂=4atm
Résultat
V₂ = P₁V₁/P₂ = 2×4/4 = 2L

Questions fréquentes

When should I use ideal gas law vs combined?

Ideal: when n (moles) is constant or unknown. Combined: when gas amount is fixed, conditions change.

What temperature units should I use?

Always Kelvin (K = °C + 273.15) in gas law equations. Celsius and Fahrenheit don't work.

Is the ideal gas approximation accurate?

Good for most gases at normal conditions. Poor at high pressure or low temperature. Use van der Waals for precision.

Paramètres