平均自由程计算器
计算气体分子两次碰撞之间的平均自由程。
Gas Density
1.2925 g/L
Gas Density vs Pressure (P)
公式
## 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.
计算示例
Calculate the density of air (avg M = 28.97 g/mol) at 1 atm and 273.15 K.
- 01d = PM / (RT)
- 02d = (1)(28.97) / (0.08206 × 273.15)
- 03d = 28.97 / 22.414
- 04d = 1.292 g/L
常见问题
Why does gas density depend on pressure and temperature?
Unlike liquids, gases are compressible. Higher pressure packs more molecules into a given volume, increasing density. Higher temperature expands gas, decreasing density.
What is the density of air at STP?
Air has an average molar mass of about 28.97 g/mol. At STP (1 atm, 273.15 K), its density is approximately 1.29 g/L.
Can I use this for real gases?
At moderate conditions it works well. For very high pressures or low temperatures, use the van der Waals equation or compressibility factor corrections.
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