Free eneigy change

The free-eneigy change for ATP hydrolysis is - 30.5 kJ/mol under standard conditions, but the actual free energy of hydrolysis (AG) of ATP in living cells is very different the cellular concentrations of ATP, ADP,... [Pg.496]

This is the free-eneigy change for the oxidation-reduction reaction at pH 7, when acetaldehyde, ethanol, NAD+, and NADH are all present at 1.00 m concentrations. If, instead, acetaldehyde and NADH were present at 1.00 Mbut ethanol and NAD+ were present at 0.100 m, the value for AG would be calculated as follows. First,... [Pg.511]

The standard free-eneigy change for an oxidation-reduction reaction is directly proportional to the difference in standard reduction potentials of the two half-cells ... [Pg.516]

Calculate the standard free-eneigy changes of the following metabolically important enzyme-catalyzed reactions at 25 °C and pH 7.0, using the equilibrium constants given. [Pg.518]

Experimental Determination of AG ° for ATP Hydrolysis A direct measurement of the standard free-eneigy change associated with the hydrolysis of ATP is technically demanding because the minute amount of ATP remaining at equilibrium is difficult to measure accurately. The value of AG ° can be calculated indirectly, however, from the equilib-... [Pg.518]

Diagrams that show how the free eneigy changes as a reaction proceeds were introduced in Chapter 4 and are very useful. Figure 8.1 shows such a diagram for the SN2 reac-... [Pg.259]

Another way of looking at solubility equilibria to find out whether a solution is oversaturated, saturated, or unsaturated consists of calculating the fiee energy for the system in eq. 5.2. From eq. 2.58 and 2.69-2.72 one can write the free eneigy change for this equilibrium as... [Pg.89]

R. M. Lynden-Bell, J.S. van Duijneveldt and D. Frenkel, Free-Eneigy Changes on Freezing and Melting in Ductile Metals, Mol. Phys. 80 (1993) pp. 801-814... [Pg.16]

Figure 2.6. Variation of the Gibbs free energy function G and the Gibbs free eneigy change of the reaction AG with extent of reaction for reactions between pure substances, for example, solids or solids and liquids.

Cell Voltage and Its Components. The minimum voltage required for electrolysis to begin for a given set of cell conditions, such as an operational temperature of 95°C, is the sum of the cathodic and anodic reversible potentials and is known as the thermodynamic decomposition voltage, E°. E° is related to the standard free eneigy change, AG°C, for the overall chemical reaction,... [Pg.484]

AG = AH - TAS [19.11] Calculating the Gibbs free-eneigy change from enthalpy and entropy changes at constant temperature... [Pg.817]

AG = [19.18] Relating the free-eneigy change to the maximum work a process can perform... [Pg.817]

AG = AG° -b i r In Q [19.19] Calculating free-eneigy change under nonstandard conditions... [Pg.817]

Notice that at 27 "C, the entropic contribution (—TAS ) to the free-eneigy change, AG" = AH" — TAS" (Equation 19.12), is negative and greater in magnitude than the enthalpic contribution (AH"). The equilibrium constant for the NH3 n reaction, 1.4 X 10, shows that the replacement of NH3 by en is thermodynamically favorable. [Pg.977]

Fig. 4. Standard state free-eneigy changes for an enzymc Catalysed reaction showing saturation kinetics, (Eqn. 36), with the standard state chosen so that the reaction occurs above saturation.

AG° = -RTlnK [19.20] Relating the standard free-eneigy change and the equilibrium constant... [Pg.845]

Calculate the standard free-eneigy change for the following reaction at 25°C ... [Pg.683]

Expressing the free eneigy change of the system in terms of its component enthalpy and entropy changes (Gibbs equation) (666) ... [Pg.676]

The standard free-eneigy change for a chemical reaction can be used to calculate the equilibrium constant for the process. [Pg.735]

Strategy From the information given we see that neither the reactant nor the product is at its standard state of 1 atm. To determine the direchon of the net reachon, we need to calculate the free-eneigy change under nonstandard-state condihons (AG) using Equation (18.13) and the given AG° value. Note that the partial pressures are expressed as dimensionless quantities in the reaction quotient Qp. [Pg.632]

The standard entropy of a chemical reaction can be calculated from the absolute entropies of reactants and products. The third law of thermodynamics states that the entropy of a perfect crystalline substance is zero at 0 K. This law enables us to measure the absolute entropies of substances. Under conditions of constant temperature and pressure, the free-eneigy change AG is less than zero for a spontaneous process and greater than zero for a nonsponta-neous process. For an equilibrium process, AG = 0. [Pg.635]

AfG means the Gibbs free-eneigy change during the reaction under standard conditions of 1 bar... [Pg.61]

Free Eneigy Change and Reaction Spontaneity Standard Free Energy Changes Free Eneigy and Work Temperature and Reaction Spontaneity Coupling of Reactions... [Pg.653]

The fitee-energy change (AG) is determined using the standard free-eneigy change (A(7 ) and the reaction quotient (0. [Pg.750]

Under ordinary atmospheric conditions (1 atm and 25°C), water will not spontaneously decompose to form hydrogen and oxygen gas because the standard free-eneigy change for the reaction is a large positive quantity ... [Pg.780]

Heat of reaction, free-eneigy changes, and reaction equilibrium constants are discussed in more detail in Section 4 in the context of chemical-reaction equilibrium. [Pg.69]

But you also must consider the free-eneigy changes that accompany the separated solvated reactants coming together into the cage. We will introduce this correction. [Pg.465]

At equilibrium, Qis the equilibrium constant for the reaction. The free-eneigy change for the reaction is zero, and Equation (27) reduces to Equation (28) ... [Pg.1069]

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