Gases & Vapor

These tools cover the state of a gas and liquid-vapor equilibrium. You can solve the ideal gas law PV = nRT for whichever quantity is unknown, find the partial pressure of each component of a gas mixture with Dalton’s law, and calculate the vapor pressure of water at a given temperature from the Antoine equation.

Ideal Gas Law Calculator (PV=nRT)

Using the ideal gas law PV=nRT, enter 3 of pressure, volume, amount of substance (moles), and temperature to calculate the remaining value.

Partial Pressure Calculator (Dalton's Law)

Calculate the partial pressure of each gas in a mixture from the total pressure and each component's mole fraction (or moles), using Dalton's Law of Partial Pressures: P_i = x_i × P_total.

Water Vapor Pressure Calculator (Antoine Equation)

Enter a temperature (°C or °F) to calculate the vapor pressure of water in mmHg, kPa, atm, and bar using the widely used Antoine equation. Change the ambient pressure to see how altitude lowers the boiling point.