Chapters 11, 12 Chemistry 102 - EXAM 1

intramolecular forces

covalent and ionic bonds that cause substances to form molecules and formula units; primarily impacts the chemical properties of substances

intermolecular forces

interactions that influence different properties of molecules such as phase, viscosity, surface tension, and more.

ion-dipole forces

an attractive force that results from the electrostatic attraction between an ion and a neutral molecule with a dipole (polar covalent).

• smaller ions and/or higher charges will have stronger forms of these interactions

dipole-dipole forces

an attractive force that results from the electrostatic attraction between the positive dipole of one molecule and the negative dipole of another.

• this type of IMF typically with polarity

london dispersion forces (LDFs)

type of IMF where the random motions of electrons in an atom or nonpolar molecule can cause the formation of an instantaneous dipole that induces dipoles in surrounding molecules

• has a weak and short range

• increases in strength with higher molecular weights and more linear molecules

Hydrogen bonding

a special type of dipole-dipole interaction that exists between the lone pair of the most electronegative atoms (O,N,F) and an H atom

• much stronger than most dipole-dipole interactions and increases IMF to significant points beyond what is expected on the basis of mass

viscosity

resistance of liquid to flow

surface tension

resistance of liquid to spread out an increase its surface area

vapor pressure

partial pressure of a gas in equilibrium w/ a liquid at a constant temperature

normal boiling point

temperature at which boiling occurs at exactly one atmosphere

normal melting point

temperature at which melting occurs at exactly one atmosphere

critical point

combination of temperature and pressure beyond which a gas cannot be liquified

supercritical fluid

a state of matter beyond the critical point that is neither liquid nor gas

solid

state of matter wherein the forces between the atoms, ions or molecules are sufficiently strong to hold the particles in fixed positions, where they vibrate but have little to no translational or rotational motion

amorphous solid

state of matter where atoms, molecules or ions are distributed randomly in solid

crystalline solid

state of matter where ions, atoms or molecules are organized in a structured/repeating pattern

molecular solid

solid composed of individual molecules with IMFs holding the particles in the solid state

• soft, does not conduct electricity

metallic solid

solids composed solely of metal atoms

• hard or soft and conducts electricity

ionic solid

solid composed of ions attracted to one another via electrostatic attraction

• hard and brittle; conducts electricity in solution

covalent network solid

solid consisting of atoms covalently bonded to one another in a 3-dimensional array

• hard and typically does not conduct electricity (in most cases)

simple cubic unit cell

unit cell where atoms are arranged in a 3-dimensional cube with an atom in each corner

body centered unit cell

unit cell where atoms are arranged in a 3-dimensional cube with an atom in each corner, as well as one in the center

face centered unit cell

unit cell where atoms are arranged in a 3-dimensional cube with an atom in each corner, as well as one in the center of each face of the cube