Clapeyron equation (also called the Clausius-Clapeyron equation) is a relation between pressure and temperature of two phases of a pure substance that are in equilibrium,
where ΔtrsS is the difference in entropy between the phases and ΔtrsV the corresponding difference in volume.
Einstein equation is the mass-energy relationship introduced by Albert Einstein in 1905 in the form E = mc2, where E is a quantity of energy, m its mass, and c is the speed of light. It presents the concept that energy possesses mass.
For general reaction of some redox system
dependence of electrode potential of redox system upon activity of oxidised and reduced form in solution is described in Nernst’s equation for electrode potential:
where E = to electrode potential of redox system
E° = standard electrode potential of redox system
R = universal gas constant
T = thermodymical temperature
F = Faraday’s constant
z = number of electrons exchanged in redox reaction
aO = activity of oxidised form
aR = activity of reduced form
n = stechiometrical coefficient of oxidised form
m = stechiometrical coefficient of reduced form
Schrödinger equation is the basic equation of wave mechanics which, for systems not dependent on time, takes the form:
where Ψ is the wavefunction, V is the potential energy expressed as a function of the spatial coordinates, E its total energy, 2 is the Laplacian operator, h is Planck’s constant, and m is the mass.
Thermochemical equation is a compact equation representing a chemical reaction that describes both the stoichiometry and the energetics of the reaction. For example, the thermochemical equation
means When one mole of gaseous methane is burned in two moles of oxygen gas, one mole of carbon dioxide gas and 2 moles of steam are produced, and 2 220 kJ of heat are released.
Van der Waals’ equation is an equation of state for real fluids which takes the form:
where p is pressure, Vm is molar volume, T is temperature, R is the molar gas constant, and a and b are characteristic parameters of the substance which describe the effect of attractive and repulsive intermolecular forces.
Van’t Hoff equation is the equation expressing the temperature dependence on the equilibrium constant K of a chemical reaction:
where ΔrH° is the standard enthalpy of reaction, R the molar gas constant, and T the temperature.
In 1889, Svante Arrhenius explained the variation of rate constants with temperature for several elementary reactions using the relationship
where the rate constant k is the total frequency of collisions between reaction molecules A times the fraction of collisions exp(-Ea/RT) that have an energy that exceeds a threshold activation energy Ea at a temperature of T (in kelvin). R is the universal gas constant.
Navier-Stokes equations are a set of complex equations for the motion of a viscous fluid subject to external forces.
Aqua regia is a mixture of one volume part of nitric acid (HNO3) and three volume parts of hydrochloric acid (HCl). Dissolving of gold in aqua regia is described by the following equation:
Generalic, Eni. "Ilkovic equation." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. {Date of access}. <https://glossary.periodni.com>.
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