Entropy & Free Energy

Flashcards covering key concepts related to entropy and free energy in thermodynamics.

Entropy (S)

A measure of disorder in a system.

Increasing Entropy

Reactions that are spontaneous and favor disorder.

Exothermic Reaction

A reaction that releases energy, typically spontaneous.

Endothermic Reaction

A reaction that absorbs energy, can be spontaneous under certain conditions.

Thermodynamically-favored

A reaction which tends to proceed under given conditions.

Non-Spontaneous

Reactions that do not occur without external influence.

ΔS > 0

Indicates increasing disorder or entropy.

ΔS < 0

Indicates decreasing disorder or entropy.

ΔG < 0

Indicates a spontaneous reaction.

ΔG > 0

Indicates a non-spontaneous reaction.

K (Equilibrium constant)

A measure of the ratio of products to reactants at equilibrium.

R-constant (8.314)

The universal gas constant used in free energy calculations.

Spontaneous Reaction

A reaction that occurs naturally without external energy input.

Product-favored

Indicates that products are favored at equilibrium.

Reactant-favored

Indicates that reactants are favored at equilibrium.

Relationship of moles to entropy

More moles of gas increase entropy; fewer moles decrease entropy.

Significance of Temperature

Higher temperatures typically lead to increased entropy.

Spontaneous at Low Temperatures

Endothermic reactions that increase entropy only at low temperatures.

Spontaneous at High Temperatures

Exothermic reactions that decrease entropy only at high temperatures.