Gibbs Free Energy and Thermodynamics

Flashcards covering key topics in Gibbs Free Energy and Thermodynamics for exam preparation.

What is the First Law of Thermodynamics?

Energy cannot be created or destroyed; the energy gained by a system must equal the energy lost by the surroundings.

What does the Second Law of Thermodynamics state about spontaneous processes?

For any spontaneous process, the entropy of the universe increases.

Define a spontaneous process in chemistry.

A reaction or process that occurs by itself under a given set of conditions.

What hypothesis is often true about exothermic and endothermic processes?

Exothermic processes (ΔH < 0) are generally spontaneous, while endothermic processes (ΔH > 0) may be nonspontaneous.

What drives a spontaneous process according to the spreading out of energy hypothesis?

The spreading out of energy drives spontaneous processes.

What is entropy (S)?

A thermodynamic property that describes the distribution of a system's energy over available energy levels.

What happens to the entropy as the number of microstates (W) increases?

Entropy increases with increasing number of microstates.

What is the formula for calculating entropy based on microstates?

S = kB ln W, where kB is the Boltzmann constant.

What processes generally result in an increase in entropy?

Melting, evaporation, and reactions where the number of gas moles increases.

What is the significance of ΔSuniverse in relation to spontaneity?

If ΔSuniverse > 0, the process is spontaneous.

Explain the relationship between ΔG and spontaneity.

If ΔG < 0, the reaction is spontaneous; if ΔG > 0, the reaction is non-spontaneous; if ΔG = 0, the reaction is at equilibrium.

How can standard change in free energy (ΔG°) be calculated?

ΔG° can be calculated from enthalpy and entropy data, or from tabulated ΔGf° data.

What is the difference between ΔG and ΔG°?

ΔG is the Gibbs free energy change under non-standard conditions, whereas ΔG° is the change under standard conditions.

What does it indicate if a reaction has ΔG° < 0?

The reaction is spontaneous under standard conditions.

Why does temperature affect spontaneity according to Gibbs free energy?

Temperature impacts the balance between enthalpy and entropy contributions to ΔG.

What is the third Law of Thermodynamics?

The entropy of a perfect crystal at absolute zero (0 K) is zero.

Describe how ΔG relates to the equilibrium constant (K).

ΔG° = -RT ln K; K indicates the direction of spontaneity.

Under what conditions does a non-spontaneous reaction occur spontaneously?

By coupling it with a spontaneous reaction or changing conditions such as temperature.

What process in mitochondria is considered non-spontaneous?

The process of synthesizing ATP from ADP is non-spontaneous.

What is a microstate?

The particular way in which the energy of a state is distributed within the system at a given point in time.