4 Isobaric equilibrium in a two –component system.Write the answer? isobaric processes
These take place at constant pressure
p = constant, so V/T = constant
Q = positive
ΔU = positive
W = positive An isobaric process is a thermodynamic process in which the pressure stays constant: ΔP = 0. The heat transferred to the system does work, but also changes the internal energy of the system. This article uses the chemistry sign convention for work, where positive work is work done on the system. Using this convention, by the first law of thermodynamics isobaric heat addition – the compressed air then runs through a combustion chamber, where fuel is burned and air or another medium is heated (2 → 3). It is a constant-pressure process, since the chamber is open to flow in and out. The net heat added is given by Qadd = H3 - H2
5Thermodynamics of an open system and the chemical potentional.Write the answer?
In
thermodynamics, chemical potential, also known as partial molar free
energy, is a form of potential energy that can be absorbed or
released during a chemical reaction or phase transition. The chemical
potential of a species in a mixture is defined as the rate of change
of a free energy of a thermodynamic system with respect to the change
in the number of atoms or molecules of the species that are added to
the system. Thus, it is the partial derivative of the free energy
with respect to the amount of the species, all other species'
concentrations in the mixture remaining constant. When both
temperature and pressure are held constant, chemical potential is the
partial molar Gibbs free energy. At chemical equilibrium or in phase
equilibrium the total sum of chemical potentials is zero, as the free
energy is at a minimum. In semiconductor physics, the chemical
potential of a system of electrons at a temperature of zero Kelvin is
known as the Fermi energy. The chemical potential of a substance i is
the partial molar derivative of the free energy G, the enthalpy H,
the Helmholtz energy A, or the internal energy U of substance i:
6Activity.Activity coefficient. Write the answer?
an activity coefficient is a factor used in thermodynamics to account for deviations from ideal behaviour in a mixture of chemical substances.[1] In an ideal mixture, the microscopic interactions between each pair of chemical species are the same (or macroscopically equivalent, the enthalpy change of solution and volume variation in mixing is zero) and, as a result, properties of the mixtures can be expressed directly in terms of simple concentrations or partial pressures of the substances present e.g. Raoult's law. Deviations from ideality are accommodated by modifying the concentration by an activity coefficient. Analogously, expressions involving gases can be adjusted for non-ideality by scaling partial pressures by a fugacity coefficient.
{\displaystyle a_{\mathrm {B} }=x_{\mathrm {B} }\gamma _{\mathrm {B} }}7Standard reaction enthalpy.Define the standard state!
Enthalpy, the sum of the internal energy and the product of the pressure and volume of a thermodynamic system. Enthalpy is an energy-like property or state function—it has the dimensions of energy , and its value is determined entirely by the temperature, pressure, and composition of the system and not by its history. In symbols, the enthalpy, H, equals the sum of the internal energy, E, and the product of the pressure, P, and volume, V, of the system: H = E + PV.
The standard enthalpy of reaction (denoted ΔHr⊖) is the enthalpy change that occurs in a system when matter is transformed by a given chemical reaction, when all reactants and products are in their standard states. standard state: In chemistry, a reference point used to calculate a material’s (pure substance, mixture, or solution) properties under different conditions.
standard enthalpy of formation: The change in enthalpy that accompanies the formation of one mole of a compound from its elements, with all substances in their standard states; also called “standard heat of formation.”
enthalpy of solution: The heat association with dissolving a particular solute in a particular solvent.