Chem 114 Lecture Notes: Entropy and Spontaneity

This set of flashcards covers key vocabulary and concepts related to entropy, spontaneity, and collagitive properties discussed in the Chem 114 lectures.

Entropy

A measure of the possible number of configurations of a system.

Gibb's Free Energy (G)

A measure of chemical potential energy; determines if a reaction is spontaneous.

Second Law of Thermodynamics

States that for every spontaneous change, there is an increase in the entropy of the universe.

ΔSuniverse

The change in entropy of the universe, related to both system and surroundings.

Molarity (M)

A measure of concentration; moles of solute per liter of solution.

Molality (m)

A measure of concentration; moles of solute per kilogram of solvent.

Van der Waals forces

The forces that cause particles to attract or repel each other.

Raoult's Law

Psolvent = Xsolvent • Posolvent; describes how the vapor pressure of a solvent is affected by solute.

Boiling Point Elevation

The increase in the boiling point of a solvent when a solute is added.

Freezing Point Depression

The decrease in the freezing point of a solvent when a solute is added.

Osmotic Pressure

The pressure required to stop osmosis; Π = iMRT.

Colligative Properties

Properties that depend on the number of solute particles in a solution.

Ideal Solution

A solution that behaves according to Raoult's Law; interactions between solute and solvent are similar.

Entropic Effect

The effect that causes the stability of a solution when solute particles are added.

Transition Temperatures

Temperatures at which reactions go from spontaneous to non-spontaneous or vice versa.

ΔG = ΔH - TΔS

Equation used to calculate free energy change of a reaction.

ΔSsystem > 0

Indicates an increase in the number of possible configurations of a system.

ΔH < 0

Indicates an exothermic reaction.

ΔH > 0

Indicates an endothermic reaction.

Spontaneous Process

A process that increases the entropy of the universe, occurring without external intervention.

Non-spontaneous Process

A process that does not occur without external intervention.

Reversible Process

A process in which the forward and reverse directions occur at the same rates.