Gas-phase ion chemistry Gas-phase ion chemistry Gas phase ion chemistry is a field of science encompassed within both chemistry and physics. It is the science that studies ions and molecules in the gas phase, most often enabled by some form of mass spectrometry. By far the most important applications for this science is in studying the thermodynamics and kinetics of reactions. For example, one application is in studying the thermodynamics of the solvation of ions. Ions with small solvation spheres of 1, 2, 3... solvent molecules can be studied in the gas phase and then extrapolated to bulk solution. Transition state theory is
A priori probability case of the hydrogen atom or Coulomb potential (where the evaluation of the phase space volume for constant energy is more complicated) one knows that the quantum mechanical degeneracy is formula_56 with formula_57. Thus in this case formula_58. In statistical mechanics (see any book) one derives the so-called distribution functions formula_59 for various statistics. In the case of Fermi-Dirac statistics and Bose-Einstein statistics these functions are respectively These functions are derived for (1) a system in dynamic equilibrium (i.e. under steady, uniform conditions) with (2) total (and huge) number of particles formula_61 (this condition determines the constant formula_62), and (3)