Chemistry Lecture: Intermolecular Forces, Solutions, and Solubility

This flashcard set covers the chemistry of solids and liquids, the thermodynamics of solution formation, solubility rules, and real-world applications including vitamins and environmental toxins.

Hexane

A hydrocarbon containing only carbon and hydrogen atoms that is non-polar and exhibits only dispersion forces.

Intermolecular Forces (IMF) in Water

Water exhibits hydrogen bonding (which is the dominant force), dipole-dipole interactions, and dispersion forces.

Molecular Solid

A type of solid where discrete molecules, such as diatomic iodine ($I_2$), are held together by intermolecular forces.

Network Atomic Solid

A solid structure, such as a diamond, where hundreds of atoms are interconnected in a continuous network.

Ionic Compound

A compound formed from a metal and a non-metal, such as potassium permanganate ($KMnO_4$), where electrons are transferred.

Enthalpy of Solution ($\Delta H_{soln}$)

The sum of the energy needed to break the intermolecular forces of the solute ($\Delta H_1$) and solvent ($\Delta H_2$), and the enthalpy released during the formation of new intermolecular forces ($\Delta H_3$).

Exothermic Solution Process

A process where the intermolecular forces formed in the solution are stronger than the original forces, releasing more energy than was required to break the starting IMFs.

Endothermic Solution Process

A process where it takes more energy to break the original intermolecular forces than is released upon reforming them in a solution, resulting in a positive $\Delta H$.

Lattice Enthalpy

The enthalpy change associated with breaking apart the intermolecular forces of a pure ionic solid to turn it into a gas.

Enthalpy of Hydration

The enthalpy change when gaseous ions mix with a solvent; it accounts for breaking the solvent's IMFs and forming new interactions in the solution.

Like Dissolves Like

A general principle stating that polar solvents dissolve polar solutes and non-polar solvents dissolve non-polar solutes.

Miscible

A term used to describe two substances that mix together to form a solution without significant resistance.

Entropy ($S$)

A measure of the disorder of a system; in solutions, it generally increases due to the expansion of volume and the increase in microstates.

Microstates

The number of potential positions and arrangements available for a particular compound in a system.

Gibbs Free Energy Equation for Solutions

The thermodynamic equation $\Delta G = \Delta H - T\Delta S$ used to determine if mixing will be spontaneous (indicated by a negative $\Delta G$).

Fat-Soluble Vitamins

Vitamins such as A, D, E, and K that are non-polar and stored in adipose (fat) tissue.

Water-Soluble Vitamins

Vitamins such as C and B12 that are polar and can be processed and excreted by the kidneys.

Hypervitaminosis

A condition resulting from an overdose of vitamins, particularly fat-soluble ones like Vitamin A, which can cause liver damage.

Scurvy

A disease caused by a deficiency in Vitamin C, historically common among sailors.

DDT

A stable, non-polar pesticide that hyperaccumulates in the environment and can lead to thin bird eggshells and increased mortality in wildlife.