Molar Mass of Gas

Molar Mass of a Gas Formula
\( M \;=\;  \dfrac{ m \cdot R \cdot T  }{ p \cdot V  } \)     (Molar Mass of a Gas) \( m \;=\;  \dfrac{ M \cdot p \cdot V  }{ R \cdot T  } \) \( R \;=\;  \dfrac{ M \cdot p \cdot V  }{ m \cdot T  } \) \( T \;=\;  \dfrac{ M \cdot p \cdot V  }{ m \cdot R  } \) \( p \;=\;  \dfrac{ m \cdot R \cdot T  }{ M \cdot V  } \) \( V \;=\;  \dfrac{ m \cdot R \cdot T  }{ M \cdot p  } \)
Symbol	English	Metric
\( M \) = Molar Mass	\( lbm\;/\; mol\)	\(g \;/\; mol\)
\( m \) = Mass of the Gas	\(lbm\)	\(g\)
\( R \) = Gas Constant	\( lbf-ft \;/\; bmol-R\)	\( J \;/\; kmol-K\)
\( T \) = Temperature	\(^\circ R \)	\(^\circ K \)
\( p \) = Pressure (psi)	\(lbf\;/\;in^2\)	\( Pa \)
\( V \) = Volume	\( in^3 \)	\( mm^3 \)

Molar mass of a gas is the mass of one mole of the gas, meaning the mass of \(6.02214076 \;x\; 10^{23} \) per \(mol^{-1} \) molecules of that substance.  It is usually expressed in grams per mole (\(g/mol\)) and is determined from the chemical formula of the gas by adding up the atomic masses of all the atoms in one molecule.  Molar mass is important because it allows scientists to convert between the mass of a gas sample and the number of moles, which is essential for calculations involving gas behavior and the ideal gas law.

Also the molar mass of a gas can be used to determine important gas properties in real-world calculations.  For instance, molar mass helps relate the density of a gas to its pressure and temperature through the ideal gas law, since gases with larger molar masses are generally denser under the same conditions.  It is also essential when comparing different gases, calculating the average molar mass of gas mixtures such as air, and converting between molecular-level measurements and laboratory-scale quantities.