Molecular Orbitals and Kinetic Molecular Theory of Gases

Vocabulary flashcards covering concepts from molecular orbital theory, states of matter, kinetic molecular theory, Maxwell-Boltzmann distributions, and pressure units.

Dr. Loudy's Bond Order Mnemonic

A pattern ($1010$, $123210$) used to determine the bond order of simple row two substances by mapping total electron counts from $2$ to $20$ (in increments of two).

Three Center Two Electron Bonds

A molecular orbital theory concept used to explain hypervalency in row three substances and below, instead of merely placing electrons into d orbitals.

Solid Matter

A state of matter possessing a definite shape and a definite volume, in which particles have very little room to move.

Liquid Matter

A state of matter possessing an indefinite shape and a definite volume, where particles have degrees of freedom to move around while remaining close together.

Gas

A phase of matter with indefinite shape and indefinite volume that expands to take the exact shape and volume of its container.

Kinetic Molecular Theory (KMT)

A modern theory describing gas behavior based on assumptions that particle size can be ignored, collisions are completely elastic, and average kinetic energy is proportional to absolute temperature.

Kelvin ($K$)

An absolute temperature scale used in gas laws and kinetic molecular theory that is directly proportional to average kinetic energy.

Elastic Collision

A type of collision assumed in kinetic molecular theory where colliding particles rebound with no permanent deformation after impact.

Inelastic Collision

A collision resulting in permanent disfigurement or deformation of the colliding bodies, such as the crumple zones of modern cars designed to absorb energy.

van der Waals Equation

An equation formulated to correct for the breakdown of kinetic molecular theory assumptions in niche or non-ideal scenarios.

Maxwell Boltzmann Distribution Plot

A graphical plot showing the distribution of velocities for gas populations at a given temperature or for a single gas across varying temperatures.

Mole

A chemical unit representing a specific quantity of items, defined numerically as $6.02 \times 10^{23}$.

Molecular Weight ($mW$)

The mass of a substance expressed as the number of grams in one mole ($\text{g}\,\text{mol}^{-1}$), which is inversely proportional to average gas velocity at constant temperature.

Mean Free Path

The random, zigzag path traveled by gas particles as they collide frequently, preventing them from moving straight and delaying their propagation over distances.

Pascal

The standard unit of pressure, defined physically as one newton per square meter ($\text{N}\,\text{m}^{-2}$).

Barometer

A device developed by the Italian scientist Poraceli that measures atmospheric pressure by the height of mercury forced up a tube.

Torr

A unit of pressure named after the Italian scientist Poraceli that is directly based on the measurement of millimeters of mercury.