### Key Concepts and Summary

The ideal gas law can be used to derive a number of convenient equations relating directly measured quantities to properties of interest for gaseous substances and mixtures. Appropriate rearrangement of the ideal gas equation may be made to permit the calculation of gas densities and molar masses. Dalton’s law of partial pressures may be used to relate measured gas pressures for gaseous mixtures to their compositions. Avogadro’s law may be used in stoichiometric computations for chemical reactions involving gaseous reactants or products.

### Key Equations

P = _{Total}P + _{A}P + _{B}P + … = Ʃ_{C}_{i}P_{i} |

P = _{A}X_{A} P_{Total} |

$X_A=\frac{n_A}{n_{Total}}$ |