B
The symbol for free-energy change is ΔG (delta G). It represents the change in Gibbs free energy during a chemical reaction, which determines whether the reaction is spontaneous or non-spontaneous.
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)whereG is Gibbs free energyH is EnthalpyT is absolute temperature (when T is given in Kelvin or Rankine it is an absolute temperature)S is EntropyIn this caseH2 - H1 = 125 kJT = 293 KS2 - S1 = 35 J/K = 0.035 kJ/Kso doing the math you getG2 - 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.
Exergonic reactions indicate a negative change in Gibbs free energy, which in English means that the reactions are spontaneous and do not require addition of energy. The exchange of oxygen and carbon dioxide in blood and lungs is an example. It is the concentration gradient that runs these exchanges passively, without additional energy from the cells.
A process is spontaneous if it occurs without any external influence or assistance. One way to determine if a process is spontaneous is by calculating the change in Gibbs free energy (G). If G is negative, the process is spontaneous.
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.
For a spontaneous reaction, the change in entropy (delta S) is typically positive.
No, an exothermic reaction is not always spontaneous. The spontaneity of a reaction depends on factors such as temperature, pressure, and the entropy change of the system.
When the delta G is negative the reaction is said to be spontaneous or in other words favorable. It also means the reaction is irreversible once full product concentration is reached. If delta G is positive, the reaction is unfavorable thus can easily be reversed. If it is zero it is at equilibrium.
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.
The first of two factors that determine whether a reaction is spontaneous or non-spontaneous is entropy. The second is energy. For a reaction to be spontaneous, it must have both of these factors.
To determine if a reaction is spontaneous or non-spontaneous at 298 K, we can use the Gibbs free energy equation, ΔG = ΔH - TΔS. If ΔG is negative, the reaction is spontaneous; if ΔG is positive, it is non-spontaneous. The values of ΔH (enthalpy change) and ΔS (entropy change) must be known to evaluate the spontaneity at this temperature. Without specific values for ΔH and ΔS, we cannot definitively conclude the spontaneity.
The symbol for free-energy change is ΔG (delta G). It represents the change in Gibbs free energy during a chemical reaction, which determines whether the reaction is spontaneous or non-spontaneous.
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.
A reaction is always spontaneous when it results in an increase in entropy (disorder) and occurs at a constant temperature and pressure, according to the second law of thermodynamics. Additionally, reactions that release energy, such as exothermic reactions, are often spontaneous. However, spontaneity also depends on the Gibbs free energy change; a negative Gibbs free energy change (ΔG < 0) indicates that a reaction is spontaneous under the given conditions.
To determine the temperature at which the decomposition of KClO4 is spontaneous, you need to know the Gibbs free energy change (∆G) for the reaction. If ∆G is negative, the reaction is spontaneous. Use the equation ∆G = ∆H - T∆S, where ∆H is the enthalpy change, ∆S is the entropy change, and T is the temperature in Kelvin. Set ∆G to 0 and solve for T to find the temperature at which the decomposition becomes spontaneous.
In a spontaneous reaction, the change in Gibbs free energy (ΔG) is negative, indicating that the reaction can occur without the input of external energy. This negative value reflects a decrease in the system's free energy, driving the reaction forward toward equilibrium. A positive ΔG, on the other hand, suggests that the reaction is non-spontaneous and requires energy input to proceed.
A reaction is always spontaneous when the change in Gibbs free energy (ΔG) is negative. This occurs when the enthalpy change (ΔH) is negative (exothermic reaction) and the entropy change (ΔS) is positive, particularly at all temperatures. Even if ΔH is positive, if ΔS is sufficiently large and positive, the reaction can still be spontaneous at high temperatures, as the term TΔS will outweigh ΔH.