Free Gas Density Calculator

Calculate the density of a gas from its molar mass, pressure, and temperature using the ideal gas law rearranged as d = PM/(RT).

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atm
g/mol
K

Gas Density

1.2925 g/L

Gas Density vs Pressure (P)

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Gas Density from Ideal Gas Law

Formula

d = PM / (RT)

Where:

  • d = density (g/L)
  • P = pressure (atm)
  • M = molar mass (g/mol)
  • R = 0.08206 L·atm/(mol·K)
  • T = temperature (K)

    • Derived from PV = nRT by substituting n = mass/M and d = mass/V.

    Example Calculation

    Calculate the density of air (avg M = 28.97 g/mol) at 1 atm and 273.15 K.

    1. 01d = PM / (RT)
    2. 02d = (1)(28.97) / (0.08206 × 273.15)
    3. 03d = 28.97 / 22.414
    4. 04d = 1.292 g/L

    Frequently Asked Questions

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