Thermodynamics and Free Energy

These flashcards cover key terms and concepts related to thermodynamics and free energy, essential for understanding the spontaneous processes and their characteristics.

Spontaneous process

A process that occurs without outside intervention.

Nonspontaneous process

A process that occurs only as long as energy is continually added to the system.

Exothermic process

A spontaneous process that releases heat.

Endothermic process

A spontaneous process where energy is absorbed, resulting in a positive change in enthalpy (ΔH > 0).

Thermodynamic Entropy (S)

A measure of how dispersed the energy in a system is at a specific temperature.

Second Law of Thermodynamics

The principle stating that the total entropy of the universe increases in any spontaneous process.

Isothermal process

A process that occurs at constant temperature.

Reversible process

A process that can be reversed without net energy flow to the system or surroundings.

Free Energy (G)

The maximum energy released by a process occurring at constant temperature and pressure, available to do useful work.

Gibbs Free Energy equation

$riangle G = riangle H - T riangle S$, relates enthalpy, entropy, and temperature for a process.

Third Law of Thermodynamics

States that the entropy of a perfect crystal is zero at absolute zero.

Standard molar entropy (S°)

The absolute entropy of one mole of a substance in its standard state at 298 K and one bar of pressure.

Quantized Energy States

Different molecular states related to molecular motion that are separated by specific energies.

Boltzmann equation

$S = k_B ext{ln}(W)$, where S is entropy, W is the number of microstates, and $k_B$ is the Boltzmann constant.

Spontaneous Chemical Processes

Processes that either increase entropy (ΔS > 0) or are exothermic (ΔH < 0) relate to spontaneity.

Entropy Change (ΔS)

Calculated by comparing the final and initial states of the system: $riangle S = S_{final} - S_{initial}$.