Thermodynamics Quiz: Second Law and Entropy

The measure of disorder or randomness in a system. It's calculated by integrating the change in heat (dq) divided by temperature (T).

Processes that can be reversed without leaving any changes to the surrounding environment.

For reversible processes, the entropy change in an isolated system is zero. Irreversible processes will produce a positive entropy change.

Entropy change during heating or cooling of a substance is calculated using temperature and heat capacity.

A process where a gas is compressed at constant temperature. Requires calculation of entropy change.

The change in entropy (ΔS) during a constant temperature process is calculated using the ideal gas law. It accounts for the change in volume and pressure of the system.

In a reversible isothermal process, the entropy change of the system is equal in magnitude but opposite in sign to the entropy change of the surroundings, resulting in a total entropy change of zero.

In an irreversible isothermal process, the entropy change of the system is the same as in the reversible process, but the entropy change of the surroundings is greater, leading to a positive total entropy change for the universe.

The entropy of a system depends only on its current state and not how it got there. Therefore, the entropy change of the irreversible process is the same as the reversible process.

In an irreversible isothermal process, the system loses heat (q) to the surroundings. This heat is equal to the product of the number of moles (n), gas constant (R), temperature (T), and the difference in pressure between the initial and final states.

The entropy change of the surroundings is calculated by dividing the heat gained by the surroundings by the constant temperature.

The combined form expresses the conservation of energy (first law) and the increase in entropy (second law) in a single equation. It relates heat change, internal energy change, work done, and entropy change.

An isothermal process where a gas expands at constant temperature. Requires calculation of entropy change.

During expansion, entropy increases because the molecules have more space to move around, resulting in a larger number of possible microstates.

Relates partial derivatives of temperature (T) and pressure (P) with respect to volume (V) and entropy (S). It states that the partial derivative of T with respect to V at constant S equals the negative of the partial derivative of P with respect to S at constant V.

A thermodynamic property representing the total energy of a system. It includes internal energy (E), pressure (P), and volume (V).

The change in enthalpy of a system during a process. It can be calculated using the equation dH = TdS + VdP.

Relates partial derivatives of temperature (T) and volume (V) with respect to pressure (P) and entropy (S). It states that the partial derivative of T with respect to P at constant S equals the partial derivative of V with respect to S at constant P.

Thermodynamic potential representing the maximum useful work obtainable from a closed system at constant temperature and volume. It's defined as A = E - TS.

Describes how the internal energy (E) changes with respect to entropy (S) and volume (V). It is expressed as dE = (∂E/∂S)_V dS + (∂E/∂V)_S dV.

The total energy contained within a system. It includes all forms of energy, such as kinetic, potential, and chemical energy.

A mathematical operation that gives the rate of change of a function with respect to one variable, while keeping other variables constant.

A constant added to the result of an indefinite integral. It represents the unknown initial value of the function.

A measure of the average kinetic energy of the particles within a system. It's related to the movement of atoms and molecules.

A thermodynamic potential that represents the maximum amount of non-expansion work that a system can perform at constant temperature and pressure.

The Gibbs free energy (G) is related to enthalpy (H), entropy (S), and temperature (T) by the equation: G = H - TS.

Represents the change in the maximum non-expansion work that a system can perform at constant temperature and pressure.

A process is spontaneous if the change in Gibbs free energy (ΔG) is negative.

The decrease in Gibbs free energy at constant temperature and pressure is equal to the net work done by the system.

This equation shows that the maximum reversible work that a system can do at constant temperature and pressure is equal to the decrease in its Gibbs free energy.

A system will tend to undergo a process that decreases its Gibbs free energy (ΔG < 0), making it spontaneous.

Maximum reversible work is obtained when a process is carried out isothermally and isobarically (constant temperature and pressure).

It describes the change in Helmholtz free energy. Work done by the system (-dw) and the temperature change (-SdT) contribute to the change in free energy.

At constant temperature, the decrease in Helmholtz free energy equals the maximum reversible work the system can do.

It relates Helmholtz free energy change (dA) to volume change (-PdV) and temperature change (-SdT).

This equation demonstrates that the change in Helmholtz free energy with respect to temperature at constant volume is equal to negative entropy.

The change in Helmholtz free energy with respect to volume at constant temperature is equal to negative pressure.

G = H - TS

At constant temperature (T), the change in Gibbs Free Energy (dG) is equal to the product of volume (V) and change in pressure (dP). (dG)T = VdP

At constant pressure (P), the change in Gibbs Free Energy (dG) is equal to the negative product of entropy (S) and change in temperature (dT). (dG)P = -SdT

An equation relating the change in free energy (ΔG) to the change in enthalpy (ΔH) and the rate of change of free energy with temperature. It helps calculate how free energy changes with temperature.

  (G / T)   H  T   P T2

The Gibbs-Helmholtz equation helps calculate the change in free energy (ΔG) at different temperatures, providing insights into how spontaneity of a reaction changes with temperature.

The Gibbs-Helmholtz equation has two forms, one relating ΔG to ΔH, and the other relating ΔG to the rate of change of ΔG with temperature.