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It tells if the reaction will process spontaneously or not
Wiki User
∙ 11y ago
Laurie Hammes
The Gibbs free energy is the maximum amount of non-expansion work that can be extracted from a closed system. With respect to STP reacting systems, a general rule of thumb is that every system seeks to achieve a minimum of free energy. Following this rule, if the Gibbs energy for a reaction is negative, the reaction is favored and should be able to provide energy for use. If the Gibbs energy is postive, then it means energy has to be added to the system to make the change occur. Note that the sign conventin for Gibbs energy is that energy added TO the system is postive, while energy coming OUT is negative. Reactions with negative delta G are generally expected to proceed spontaneously (albeit the speed with which they will proceeed is not specified) while reactions with positive delta G will not occur spontaneously - al least from a macroscopic point of view. In reality, reactions typically go back and forth between reactants and products constantly with the direction having a negative delta G being favored. When the delta G for the forward reaction (which depends in part on the concentrations of the reactants) is equal to the detla G of the backward reaction (which depends in part on the concentration of the products backward reaction), the overall delta G is zero and you have equilibrium.
Wiki User
∙ 10y agoThe Gibbs free energy is the maximum amount of non-expansion work that can be extracted from a closed system. With respect to STP reacting systems, a general rule of thumb is that every system seeks to achieve a minimum of free energy. Following this rule, if the Gibbs energy for a reaction is negative, the reaction is favored and should be able to provide energy for use. If the Gibbs energy is postive, then it means energy has to be added to the system to make the change occur. Note that the sign conventin for Gibbs energy is that energy added TO the system is postive, while energy coming OUT is negative. Reactions with negative delta G are generally expected to proceed spontaneously (albeit the speed with which they will proceeed is not specified) while reactions with positive delta G will not occur spontaneously - al least from a macroscopic point of view. In reality, reactions typically go back and forth between reactants and products constantly with the direction having a negative delta G being favored. When the delta G for the forward reaction (which depends in part on the concentrations of the reactants) is equal to the detla G of the backward reaction (which depends in part on the concentration of the products backward reaction), the overall delta G is zero and you have equilibrium.
What is the Gibbs free energy of the reaction at 300K?
150
Why is hydrogen combustible?
Fundamentally, because the Gibbs free energy of elemental hydrogen and oxygen is substantially greater than the Gibbs free energy of the water formed by their chemical reaction, and the activation energy for the reaction is not excessively high.
What reactions will Gibbs free energy always be positive?
Since the question seems to be about reactions - and the whole idea of a reaction is that something is changing... The CHANGE in Gibbs free energy will always be positive for a spontaneous reaction. As far as whether the Gibbs free energy of a system (without the term "change" attached) ... Since Gibbs free energy is a state function, it is always defined relative to a standard state. Asking if the Gibbs free energy is positive is akin to asking how "high" something is - the answer depends on where you define zero to be. If you define 0 height to be the level of the ground you are standing on, you will get a different answer than if you define zero height to be "sea level". A cactus in Death Valley may have a positive height relative to the ground, but would actually have a negative height relative to sea level. Likewise, the Gibbs free energy of a system will be positive or negative (or zero) depending on what you define as the standard state.
According to the Gibbs free energy equation G H - TS when is a reaction always spontaneous?
when H is negative and S is positive
How does the Gibbs free energy predict spontaneity?
It tells if the reaction will process spontaneously or not
What is the Gibbs free energy of the reaction at 300K?
150
What information does gibb's free energy give about reaction?
When the Gibbs free energy for a reaction is greater than zero, the reaction is "disfavored" - won't proceed in that direction - in fact it may try go in the reverse direction if possible. When the Gibbs free energy for a reaction is less than zero, the reaction is "favored" - it should proceed as written spontaneously. When the Gibbs free energy for a reaction is exactly zero - it is in equilibrium, with the forward and back ward reactions occurring at the same rate.
Why is hydrogen combustible?
Fundamentally, because the Gibbs free energy of elemental hydrogen and oxygen is substantially greater than the Gibbs free energy of the water formed by their chemical reaction, and the activation energy for the reaction is not excessively high.
What is a negative Gibbs free-energy value an indication of?
Spontaneous reaction
What does the gibbs free energy predict?
It predicts whether or not a reaction will be spontaneous.
What does Gibbs's free energy depend on?
it depends on the entropy and enathalpy of the reaction
What does Gibbs free energy depends on?
it depends on the entropy and enathalpy of the reaction
How does Gibbs free energy predict spontaneous?
If G < 0, the reaction is spontaneous.
An endergonic reaction is a reaction in which the change in Gibbs free energy is what?
Positive (greater than 0).
What is true about the numerical value of the Gibbs free-energy change for a spontaneous reaction?
B
What is the name and symbol of the single thermodynamic quantity which determines whether or not a reaction is spontaneous?
Gibbs free energy -- symbol G. If the change in Gibbs free energy for a reaction is negative, the reaction is spontaneous. If it is zero, you are at equilibrium. If it is positive, the reaction is NOT spontaneous.G ≡ H -TS (or in another useful form dG = dH -TdS)whereH is enthalpyT is absolute temperatureS is entropy
What does it mean if a reaction is having a free energy close to zero?
If the Gibbs free energy is close to zero, the reaction is close to equilibrium.
