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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.
This is a gas-phase reaction of phosphorus vapor, above the solid, with oxygen producing excited states of (PO) 2 and HPO. [7] Another gas phase reaction is the basis of nitric oxide detection in commercial analytic instruments applied to environmental air-quality testing.
Heterogeneous catalysis typically involves solid phase catalysts and gas phase reactants. [2] In this case, there is a cycle of molecular adsorption, reaction, and desorption occurring at the catalyst surface. Thermodynamics, mass transfer, and heat transfer influence the rate (kinetics) of reaction.
In the gas phase, the comproportionation reaction is much faster because of the much higher mobility of the reacting species as illustrated, e.g., in the Claus reaction where H 2 S and SO 2 react together to form elemental sulfur. Various classical comproportionation reactions are detailed in the series of examples here below.
The phase diagram shows, in pressure–temperature space, the lines of equilibrium or phase boundaries between the three phases of solid, liquid, and gas. The curves on the phase diagram show the points where the free energy (and other derived properties) becomes non-analytic: their derivatives with respect to the coordinates (temperature and ...
As a simple example occurring in the gas phase, the reaction 2 SO 2 + O 2 → 2 SO 3 can be catalyzed by adding nitric oxide. The reaction occurs in two steps: 2 NO + O 2 → 2 NO 2 (rate-determining) NO 2 + SO 2 → NO + SO 3 (fast) The NO catalyst is regenerated. The overall rate is the rate of the slow step [15] v=2k 1 [NO] 2 [O 2].
Chemical ionization for gas phase analysis is either positive or negative. [12] Almost all neutral analytes can form positive ions through the reactions described above. In order to see a response by negative chemical ionization (NCI, also NICI), the analyte must be capable of producing a negative ion (stabilize a negative charge) for example ...
Understanding this is perhaps a "thought experiment" in chemical kinetics, but actual examples exist. A gas-phase reaction at constant temperature and pressure which results in an increase in the number of molecules will lead to an increase in volume. Inside a cylinder closed with a piston, it can proceed only by doing work on the piston.