Thermodynamics Free energy Spontaneous

Spontaneity, Entropy, and the Second Law of Thermodynamics Free Energy... 

In this chapter, the review will mainly focus on the laws of thermodynamics and their implications. The discussion includes concepts such as enthalpy, entropy, specific heat, heat capacity, Gibbs free energy, spontaneity of reactions, and related aspects. We have many ideas to discuss. So buckle up ... 

In his classic thermodynamic treatise, Gibbs [3] related wetting to a decrease of free energy. Spontaneous wetting occurs when the sum of interfacial en-... 

In thermodynamic terms, a spontaneous reaction AG < 0) may proceed only slowly without enzymes because of a large activation energy (EJ. Adding enzymes to the system does not change the free energy of either the substrates or products (and thus does not alter the AG of the reaction) but it does lower the activation energy and increase the rate of the reaction. 

The thermodynamic function used as the criterion of spontaneity for a chemical reaction is the Gibbs free energy of reaction, AG (which is commonly referred to as the reaction free energy ). This quantity is defined as the difference in molar Gibbs free energies, Gm, of the products and the reactants ... 

The second law of thermodynamics states that the total entropy of a system must increase if a process is to occur spontaneously. Entropy is the extent of disorder or randomness of the system and becomes maximum as equilibrium is approached. Under conditions of constant temperature and pressure, the relationship between the free energy change (AG) of a reacting system and the change in entropy (AS) is expressed by the following equation, which combines the two laws of thermodynamics ... 

Electrochemically, a spontaneous reaction generates a positive cell potential, Scell Thermodynamically, a spontaneous reaction has a negative change in free energy, AG. Thus, a reaction that has a negative change in free... 

An important use of the free energy function is to obtain a simple criterion for the occurrence of spontaneous processes and for thermodynamic equilibrium. According to the second law of thermodynamics,... 

Whether a reaction is spontaneous or not depends on thermodynamics. The cocktail of chemicals and the variety of chemical reactions possible depend on the local environmental conditions temperature, pressure, phase, composition and electrochemical potential. A unified description of all of these conditions of state is provided by thermodynamics and a property called the Gibbs free energy, G. Allowing for the influx of chemicals into the reaction system defines an open system with a change in the internal energy dt/ given by ... 

Our goal in this chapter is to help you learn the laws of thermodynamics, especially the concepts of entropy and free energy. It might be helpful to review Chapter 6 on thermochemistry and the writing of thermochemical equations. The concept of Gibbs free energy (G) will be useful in predicting whether or not a reaction will occur spontaneously. Just like in all the previous chapters, in order to do well you must Practice, Practice, Practice. 

One of the goals of chemists is to be able to predict if a reaction will be spontaneous. A reaction may be spontaneous if its AH is negative or if its AS is positive, but neither one is a reliable predictor by itself about whether or not a reaction will be spontaneous. Temperature also plays a part. A thermodynamic factor that takes into account the entropy, enthalpy, and temperature of the reaction would be the best indicator of spontaneity. This factor is the Gibbs free energy. 

The Gibbs free energy is a thermodynamic quantity that relates the enthalpy and entropy, and is the best indicator for whether or not a reaction is spontaneous. 

The Gibbs free energy is the best single thermodynamic indicator of whether a reaction will be spontaneous (review the Thermodynamics chapter). The Gibbs free energy for a reaction can be calculated from the E° of the reaction using the following equation ... 

Gibbs free energy The Gibbs free energy (G) is a thermodynamic function that combines the enthalpy, entropy, and temperature. AG is the best indicator of whether or not a reaction will be spontaneous. 

Partitioning is governed mainly by free energy change. The net free energy describes the overall tendency of the system to make a specific change. The concept is in accord with the laws of thermodynamics and assumes that it is the natural tendency of a system to seek spontaneously a condition of minimum energy and maximum disorder [65,192-194]. The most common form of the equation is... 

Gibbs free energy (G) is probably the most freqnently nsed quantity in thermodynamics it measnres spontaneity of a reaction or energy available to do work in a system. Free energy is a state fnnction because it is defined formally only in terms of the state fnnctions enthalpy and entropy and the state variable temperature. The Gibbs free energy is defined as... 

The thermodynamic criterion for spontaneity (feasibility) of a chemical and electrochemical reaction is that the change in free energy, AG have a negative value. Free-energy change in an oxidation-reduction reaction can be calculated from knowledge of the cell voltage ... 

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