Chemistry Concepts: Entropy, Enthalpy, and Solutions

These flashcards cover essential vocabulary and concepts related to entropy, enthalpy, and solutions as discussed in the lecture notes.

Entropy

A measure of the number of possible arrangements for a given state, higher arrangements indicate a higher probability of that state.

Second Law of Thermodynamics

States that the total entropy of the Universe must increase in any change.

Enthalpy (AH)

Heat entering or exiting a system during a phase change.

Gibbs Free Energy (G)

A function that predicts if a process is thermodynamically favorable, calculated as AG = AH - TAS.

Homogeneous mixture

A solution composed of two or more components that has a uniform composition throughout.

Solute

The minor component in a solution.

Solvent

The major component in a solution.

Saturated solution

A solution in which no more solute can dissolve.

Unsaturated solution

A solution that can still dissolve more solute.

Molarity (M)

A way of expressing concentration, calculated as moles of solute per liter of solution.

Immiscible

Describes substances that do not mix, often forming separate layers.

Miscible

Describes substances that mix completely when combined.

Dissolving process

The interaction of solute and solvent that leads to the formation of a solution.

Amphipathic molecules

Molecules that contain both polar and nonpolar parts.

Alloy

A solid solution in a metallic matrix.

Parts-per-million (ppm)

A way to express very dilute concentrations, equivalent to 1 gram of solute per 1,000,000 grams of solution.

Endothermic reaction

A reaction where heat is absorbed, resulting in a positive change in Gibbs Free Energy.

Exothermic reaction

A reaction where heat is released, resulting in a negative change in Gibbs Free Energy.

Ion-dipole interaction

Attractive forces between an ion and a polar molecule.

Phase change

A transition of a substance from one state of matter to another, such as from solid to liquid.

Freezing point depression

The process where the freezing point of a solvent is lowered by adding a solute.