Chapter 15: Entropy and Free Energy

Flashcards based on key concepts from Chapter 15 on Entropy and Free Energy.

What is the Second Law of Thermodynamics for spontaneity?

Spontaneous if the change in entropy of the universe (DSuniv) is greater than 0.

How can you determine the spontaneity of a process at constant temperature and pressure?

A process is spontaneous if the Gibbs Free Energy (DG) is negative.

What is the relationship between Gibbs Free Energy, enthalpy, and entropy?

DG = DH - TDS.

In Case 1, what are the signs of DH and DS, and what is the spontaneity?

DH < 0 and DS > 0; the process is always spontaneous.

What does DG greater than 0 indicate about a process?

The process is not spontaneous in the forward direction.

What temperature conditions lead to spontaneity when both DH and DS are positive?

At high temperatures, the process is spontaneous.

What is the formula to determine the temperature (T) required for a reaction to be spontaneous?

T = DH / DS.

How do you interpret a change in Gibbs Free Energy of 0?

The system is at equilibrium.

If DH is positive and DS is negative, what can you infer about spontaneity at all temperatures?

The process is never spontaneous.

For water freezing, under what temperature conditions is the process spontaneous?

The process is spontaneous at temperatures below 0 °C.

How do you calculate the entropy change for a phase change?

Use the equation DS = DH / T, where T is in Kelvin.