Spontaneity of reaction

Effect of Temperature, Pressure, and Concentration on Reaction Spontaneity 

Additivity of Free Energy Changes Coupled Reactions 

The ballerinas in Degas s painting The Dancers look like they have depleted their glucose by using it for energy to dance. 

To develop a general criterion for spontaneity, we will apply the principles of thermodynamics, the science that deals with heat and energy effects. Three different thermodynamic functions are of value in analyzing spontaneity. 

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the change in enthalpy (Chapter 8) a negative value of AH tends to make a reaction spontaneous. 

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You will recall that the sign of AG can be correlated with the spontaneity of reaction. We can do the same thing with AG° provided we restrict our attention to standard conditions (1 atm, 1M). 

Spectator ion An ion that, although present, takes no part in a reaction, 279,82-83, 372-373,399 Spontaneity of reaction concentration and, 465-467,475-476q entropy and, 453-458 free energy and, 458-471 pressure effects, 465-467,475-476q process, 451-453 redox, 489-490... 

Predict the spontaneity of reaction when a piece of iron is dipped into HCl solution. 

Thus the latter equation AGsystem = — 7j A Vllnjverse shows how the two criteria which can be used to assess the thermodynamic spontaneity of reactions or processes are basically identical since if ... 

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 ... 

We learned how to predict the mode of a reaction in terms of whether the reaction will be endothermic or exothermic. In this section, we will explore the dynamics and the factors that influence the spontaneity of reactions. For that, we have to be familiar with the term entropy. ... 

All interactions between elements and compounds are governed by the free energy changes available to them. Free energy is the single factor that determines the spontaneity of reaction. 

Enthalpy change is not the only consideration in the spontaneity of reactions, however, nor is it a foolproof guide. For example, even though ice melting is an endothermic process,... 

Two common questions often arise when one first learns about the Gibbs free energy Why does the sign of AG tell us about the spontaneity of reactions And what is free about free energy We address these two questions here by irsing concepts discirssed in Chapter 5 and earlier in this chapter. 

It is very convenient to define a new thermodynamic quantity in terms of H and S that will be directly useful as a criterion of spontaneity. For this purpose, the American physicist J. Willard Gibbs (1839-1903) introduced the concept of free energy, G, which is a thermodynamic quantity defined by the equation G = H — TS. This quantity gives a direct criterion for spontaneity of reaction. 

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