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The gas constant occurs in the ideal gas law: = = where P is the absolute pressure, V is the volume of gas, n is the amount of substance, m is the mass, and T is the thermodynamic temperature. R specific is the mass-specific gas constant. The gas constant is expressed in the same unit as molar heat.
A reagent, termed the titrant or titrator, [2] is prepared as a standard solution of known concentration and volume. The titrant reacts with a solution of analyte (which may also be termed the titrand [3]) to determine the analyte's concentration. The volume of titrant that reacted with the analyte is termed the titration volume.
The ratio of peak areas between the internal standard and analyte is calculated to determine analyte concentration. [12] A common type of internal standard is an isotopically labeled analogue of the analyte, which incorporates one or more atoms of 2 H, 13 C, 15 N and 18 O into its structure. [13]
Differences in the temperature between the titrant and the titrand; Evaporative losses from the surface of the rapidly mixed fluid; Heats of solution when the titrant solvent is mixed with the analyte solvent; Heat introduced by the mechanical action of stirring (minor influence); and; Heat produced by the thermistor itself (very minor influence).
Titration is a family of techniques used to determine the concentration of an analyte. [8] Titrating accurately to either the half-equivalence point or the endpoint of a titration allows the chemist to determine the amount of moles used, which can then be used to determine a concentration or composition of the titrant.
where ln denotes the natural logarithm, is the thermodynamic equilibrium constant, and R is the ideal gas constant.This equation is exact at any one temperature and all pressures, derived from the requirement that the Gibbs free energy of reaction be stationary in a state of chemical equilibrium.
The van der Waals equation of state may be written as (+) =where is the absolute temperature, is the pressure, is the molar volume and is the universal gas constant.Note that = /, where is the volume, and = /, where is the number of moles, is the number of particles, and is the Avogadro constant.
The electrochemical generation of a titrant is much more sensitive and can be much more accurately controlled than the mechanical addition of titrant using a burette drive. For example, a constant current flow of 10 μA for 100 ms is easily generated and corresponds to about 10 micrograms of titrant.