How to Calculate Gas State Transitions (P1V1/T1 = P2V2/T2)
Calculate multi-variable gas state changes step-by-step:
Enter State 1 (P1, V1, T1)
Input initial pressure, volume, and Kelvin temperature.
Enter State 2 (P2, T2)
Input final target pressure P2 and final temperature T2.
Apply Combined Law
Multiply V2 = (P1 × V1 × T2) / (P2 × T1).
View Final V2
Get exact final volume V2 in Liters.
Key Features & Unified Gas Thermodynamics
Unified Gas Law Solver
Solves simultaneous pressure, volume, and temperature variations in a single step.
Gas Moles Calculation
Calculates gas mole amount n = (P1·V1)/(R·T1).
Atmospheric Flight & Weather Balloons
Predicts high-altitude weather balloon expansion as temperature and pressure drop.
Physical Chemistry Guide: The Combined Gas Law
The Combined Gas Law unites the empirical gas laws of Robert Boyle, Jacques Charles, and Joseph Louis Gay-Lussac:(P₁ · V₁) / T₁ = (P₂ · V₂) / T₂ ⇒ V₂ = (P₁ · V₁ · T₂) / (P₂ · T₁)
Frequently Asked Questions
?When should you use the Combined Gas Law versus the Ideal Gas Law?
Use the Combined Gas Law when comparing a fixed amount of gas changing between two distinct states (State 1 → State 2). Use the Ideal Gas Law when analyzing a static gas sample (PV = nRT).