A process will be spontaneous when the change in Gibbs free energy is negative.
The change in Gibbs free energy can be calculated from the equation:
G2 - G1 = H2 - H1 - T(S2 - S1)
where
G is Gibbs free energy
H is Enthalpy
T is absolute temperature (when T is given in Kelvin or Rankine it is an absolute temperature)
S is Entropy
In this case
H2 - H1 = 125 kJ
T = 293 K
S2 - S1 = 35 J/K = 0.035 kJ/K
so doing the math you get
G2 - G1 = 125 - 293(0.35) = 22.45 > 0 so the process is not spontaneous in the direction where enthalpy change and entropy change are being measured. The reverse process would be spontaneous.
Gibbs energy accounts for both enthalpy (heat) and entropy (disorder) in a system. A reaction will be spontaneous if the Gibbs energy change is negative, which occurs when enthalpy is negative (exothermic) and/or entropy is positive (increased disorder). The relationship between Gibbs energy, enthalpy, and entropy is described by the equation ΔG = ΔH - TΔS, where T is temperature in Kelvin.
The Gibbs free energy equation considers both the enthalpy and entropy of a system, while the Helmholtz free energy equation only considers the internal energy and entropy. In thermodynamics, these equations are related through the relationship G H - TS, where G is the change in Gibbs free energy, H is the change in enthalpy, S is the change in entropy, and T is the temperature. This equation helps determine whether a reaction is spontaneous or non-spontaneous at a given temperature.
it depends on the entropy and enathalpy of the reaction
In thermodynamics, entropy and free energy are related through the equation G H - TS, where G is the change in free energy, H is the change in enthalpy, T is the temperature in Kelvin, and S is the change in entropy. This equation shows that the change in free energy is influenced by both the change in enthalpy and the change in entropy.
For a spontaneous reaction, the numerical value of the Gibbs free-energy change (ΔG) is negative, indicating that the reaction is energetically favorable and will proceed in the forward direction. This negative ΔG means that the system is releasing energy and increasing in entropy during the reaction.
Enthalpy and entropy are key factors in determining the spontaneity of a reaction, as described by Gibbs free energy (ΔG = ΔH - TΔS). A reaction is spontaneous when ΔG is negative, which can occur if the enthalpy change (ΔH) is negative (exothermic) or if the entropy change (ΔS) is positive (increased disorder). High temperatures can also enhance the effect of entropy, making reactions with positive ΔS more likely to be spontaneous. Thus, both ΔH and ΔS contribute to the overall favorability of a reaction.
It is not spontaneous.
Changing the temperature
In a chemical reaction, enthalpy, entropy, and free energy are related. Enthalpy is the heat energy exchanged during a reaction, entropy is the measure of disorder or randomness, and free energy is the energy available to do work. The relationship between these three factors is described by the Gibbs free energy equation: G H - TS, where G is the change in free energy, H is the change in enthalpy, S is the change in entropy, and T is the temperature in Kelvin. This equation shows that for a reaction to be spontaneous, the change in free energy must be negative, meaning that the enthalpy change and entropy change must work together in the right direction.
The relationship between enthalpy (H) and entropy (S) is described by the Gibbs free energy equation, ΔG = ΔH - TΔS, where ΔG is the change in Gibbs free energy, ΔH is the change in enthalpy, T is the temperature in Kelvin, and ΔS is the change in entropy. For a reaction to be spontaneous at higher temperatures but not at lower temperatures, the entropy term (TΔS) must dominate over the enthalpy term (ΔH) in the Gibbs free energy equation. This suggests that the increase in entropy with temperature plays a more significant role in driving the reaction towards spontaneity than the enthalpy change.
A reaction will be spontaneous at low temperatures if the decrease in enthalpy (change in heat content) of the reaction is greater than the decrease in entropy (measure of disorder) multiplied by the temperature. This can be represented by the equation ΔG = ΔH - TΔS, where ΔG is the change in Gibbs free energy, ΔH is the change in enthalpy, T is the temperature in Kelvin, and ΔS is the change in entropy.
A reaction that is never spontaneous has a positive Gibbs free energy change (ΔG > 0) under all conditions. This can occur when the enthalpy change (ΔH) is positive and the entropy change (ΔS) is negative, which leads to a situation where the term TΔS (temperature times the change in entropy) does not offset the positive ΔH. As a result, the overall Gibbs free energy remains positive, indicating that the reaction does not occur spontaneously.
For a spontaneous reaction, the change in entropy (delta S) is typically positive.
It tells if the reaction will process spontaneously or not
A reaction is considered spontaneous when it occurs without external intervention, typically at a specific temperature where the Gibbs free energy change (ΔG) is negative (ΔG < 0). The temperature at which a reaction becomes spontaneous can vary depending on the enthalpy (ΔH) and entropy (ΔS) changes associated with the reaction, as expressed in the Gibbs free energy equation: ΔG = ΔH - TΔS. If the entropy increases (ΔS > 0), the reaction may be spontaneous at lower temperatures, while if the enthalpy is favorable (ΔH < 0), it may be spontaneous at higher temperatures.
A reaction will be spontaneous at 298 K if the Gibbs free energy change (ΔG) for the reaction is negative. This means that the reaction will proceed in the forward direction without requiring an external input of energy. The equation ΔG = ΔH - TΔS can be used to determine if a reaction is spontaneous at a given temperature, where ΔH is the change in enthalpy and ΔS is the change in entropy.
For a spontaneous reaction, the overall change in enthalpy should be negative (exothermic). This means that the products have a lower enthalpy than the reactants, releasing energy in the form of heat.