In terms of the algebraic signs of ΔH and ΔS, under which of the following circumstances will a

step 1 According to the Gibbs free energy equation, delta G equals delta H minus T, delta S, in order f

In terms of the algebraic signs of ΔH and ΔS, under which of...

In terms of the algebraic signs of $\Delta H$ and $\Delta S,$ under which of the following circumstances will a change be spontaneous:
(a) At all temperatures?
(b) At low temperatures but not at high temperatures?
(c) At high temperatures but not at low temperatures?

Key Concepts

Temperature Dependence in Spontaneity

Temperature dependence in reaction spontaneity arises through the T?S term in the Gibbs free energy equation. The balance between ?H and T?S determines whether the reaction will be spontaneous at different temperatures. For instance, a reaction might only be spontaneous at low temperatures if the enthalpy term dominates, or at high temperatures if the entropy term becomes more significant.

Gibbs Free Energy

Gibbs free energy is the thermodynamic function used to determine the spontaneity of a process. It is defined by the equation ?G = ?H - T?S, where ?G is the change in free energy, ?H is the change in enthalpy, T is the absolute temperature, and ?S is the change in entropy. A negative ?G indicates that a process is spontaneous under constant temperature and pressure.

Enthalpy Change (?H)

Enthalpy change refers to the heat absorbed or released during a reaction at constant pressure. Its sign indicates whether a process is exothermic (negative ?H, releasing heat) or endothermic (positive ?H, absorbing heat). The sign of the enthalpy change plays a significant role in determining the temperature ranges over which a reaction may be spontaneous.

Entropy Change (?S)

Entropy change measures the degree of disorder or randomness in a system. A positive ?S signals an increase in disorder, favoring spontaneity, while a negative ?S indicates a decrease in disorder. Together with the enthalpy change, the entropy change influences the free energy and therefore the conditions under which a process is spontaneous.

Transcript

Please give Ace some feedback