Gibb's Free Energy: Spontaneous Reactions at High Temperatures

In summary, the conversation discusses the spontaneity of a reaction and whether it would occur at extremely high temperatures. According to the Gibb's Free Energy formula, a reaction is spontaneous if Delta G is negative. However, it is theoretically possible for the reaction to occur at impossible temperatures such as 999999999999999999999999 degrees Kelvin, but it has no practical significance. This is because at such high temperatures, other effects and reactions would take place instead.
  • #1
rajakavuru
1
0
Hello,
If a reaction is spontaneous when calculated using Gibb's Free Energy formula,
Delta G = Delta H - (T*Delta S)

Does it mean the reaction will occur at impossible temperatures even (such as 999999999999999999999999 degrees Kelvin)

for ex:
H2O(g) C(s) --> CO(g)+H2(g)
Delta H = 135.5 kJ
Delta S = .1488 kJ
T = 1173 Kelvin

Delta G = -39 (if delta G is negative, the reaction is spontanious, according to Gibb's Free Energy)

since this reaction is spontanious, will this occur at 99999999999999999 degrees kelvin even? (is this possible?)
 
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  • #2
Theoretically, it is. But since you cannot achieve such a temperature, it has no practical significance.
 
  • #3
No, it doesn't mean that. When temperature rises other effects/reactions tend to take place and they replace initial system.

http://en.wikipedia.org/wiki/Orders_of_magnitude_(temperature )
 
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What is Gibb's Free Energy?

Gibb's Free Energy is a thermodynamic quantity used to measure the amount of energy available in a system to do useful work. It is represented by the symbol G and is a combination of the enthalpy and entropy of a system.

How is Gibb's Free Energy related to spontaneous reactions?

Gibb's Free Energy is directly related to the spontaneity of a reaction. If the Gibb's Free Energy of a reaction is negative, the reaction is considered to be spontaneous and will occur without the need for external energy input. If it is positive, the reaction will not occur spontaneously and will require external energy input to proceed.

What is the formula for calculating Gibb's Free Energy?

The formula for calculating Gibb's Free Energy is ΔG = ΔH - TΔS, where ΔH is the change in enthalpy, T is the temperature in Kelvin, and ΔS is the change in entropy.

How does temperature affect Gibb's Free Energy?

Temperature has a significant impact on Gibb's Free Energy. As temperature increases, the value of ΔS increases and the value of ΔG decreases. This means that at higher temperatures, a reaction that may not be spontaneous at lower temperatures can become spontaneous.

Can Gibb's Free Energy be used to predict the direction of a reaction?

Yes, Gibb's Free Energy can be used to predict the direction of a reaction. If ΔG is negative, the reaction is predicted to proceed in the forward direction. If ΔG is positive, the reaction is predicted to proceed in the reverse direction. If ΔG is zero, the reaction is at equilibrium and no net change will occur.

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