Phase Changes and Intermolecular Forces Vocabulary

These flashcards cover key vocabulary from the lecture notes, including types of bonds, heat energy, intermolecular forces, and phase changes.

Intramolecular forces

Bonds inside a molecule: ionic bonds, covalent bonds, and metallic bonds. Intra - means within (covalent bonds, ionic bonds)

Intermolecular forces

Particles are bonded to other particles by intermolecular forces. Inter - means between

Heat

Energy that can be measured in Joules

Temperature

A measure of how much kinetic energy an object has

Heating Cooling Curve

Shows the temperature when changing the phase of a substance. Phase changes are physical changes, we break bonds between molecules (inter), but we do not break the chemical bonds (intra).

Polarity

Occurs when molecules have an uneven sharing of electrons. One side of the molecule is positive, the other is negative, we call this as having a dipole

Dipole-Dipole

The attractive forces between the negative end of one polar molecule and the positive end of another polar molecule.

Hydrogen Bonds

A type of Dipole - Dipole; Occurs between a Hydrogen that is covalently bonded to Fluorine, Oxygen, or Nitrogen and another F, O, or N with at least one lone pair. Five to ten times stronger than other dipole-dipole attractions

Induced Dipole - Induced Dipole

a.k.a. (London Dispersion Forces); Instantaneous charge distributions are polar.

London Dispersion Forces (LDFs)

Due to temporary clumping of electrons, and create temporary charges. The weakest type of force. All molecules have LDFs. Nonpolar molecules ONLY have LDFs.

Molar Heat of Fusion (ΔHfus)

The amount of heat needed to melt one mole of a substance from solid to a liquid. The formula to find heat used is: q = n (ΔHfus)

Molar Heat of Vaporization

The amount of heat needed to vaporize a liquid and turn it into a gas! Usually given in kJ/mol. The formula for this is: q = n(ΔHvap)

Vaporization or evaporation

Endothermic; The high-energy molecules escape the surface.

Condensation

Process by which vapor molecules convert to a liquid

Vapor Pressure

Pressure of the vapor present at equilibrium with its liquid

Crystalline solids

Solids with a regular arrangement of their components. Can be ionic, molecular, or atomic solids.

Ionic solids

Crystalline solids where components are ions.

Molecular solids

Crystalline solids where components are molecules.

Atomic solids

Crystalline solids where components are atoms.

Bonding in Metals

Metals are held together by nondirectional covalent bonds (called the electron sea model) among the closely packed atoms.