Gas Density Formula
Ideal gas relation for mass per volume
Formula
ρ = (P × M) / (R × T)
ρ: density, P: pressure, M: molar mass, R: gas constant, T: absolute temperature.
Example
Given: CO₂, M = 44.01 g/mol, P = 1.00 atm, T = 298 K, R = 0.082057 L·atm·mol⁻¹·K⁻¹.
ρ = (1.00 × 44.01) / (0.082057 × 298) g/L
ρ ≈ 44.01 / 24.45 ≈ 1.80 g/L
Answer: ≈ 1.80 g/L
Notes
- Works best for ideal gases; real gases may deviate at high P/low T.
- Use consistent units; convert M to kg/mol if you want SI density in kg/m³.