Chemistry 151: Gas Laws, Molecular Polarity, and Real Gas Corrections

Vocabulary practice flashcards covering course announcements, Lewis structures, molecular polarity, Dalton's law and mole fractions, kinetic molecular theory, and real gas corrections.

Chem 151 Final Exam

The comprehensive exam co-written by the instructor and Doctor Askel, scheduled for December 8 from 10:00 to noon.

University Three-Exam Policy

A policy permitting a student who has three exams scheduled on the same day to reschedule their center exam.

$XeF_4$ Central Lone Pairs

The two lone pairs placed on the central xenon atom because xenon is below the third period and has four leftover electrons after satisfying fluorine octets.

$XeF_4$ Polarity

A nonpolar molecule because its polar bonds are arranged at $90^{\circ}$ and $180^{\circ}$ opposite each other, causing the bond dipoles to cancel out.

Gas Collection Over Water

An experimental technique yielding a mixture of water vapor and collected gas (such as argon), where the gas pressure is calculated by subtracting water's partial pressure from the total pressure.

Mole Fraction

The ratio of the moles of an individual gas component to total moles in a mixture, defined mathematically as $\frac{n_i}{n_{\text{total}}}$.

Partial Pressure via Mole Fraction

The pressure contributed by an individual gas in a mixture, expressed as $\frac{n_i RT}{V}$ when total moles cancel out using the mole fraction.

Billiard Ball Analogy

A kinetic molecular theory description of gas particles undergoing elastic collisions and continuous motion without sticking or crashing like cars.

Average Kinetic Energy

The thermal energy of motion that averages out to the exact same value for different gases at the same temperature by balancing molecular mass and speed.

Gas Effusion / Diffusion Rate

The observation of gas escaping into another side of a container, governed by particle speed, with lighter molecules moving faster than heavier molecules.

Real Gas Pressure Correction ($a$)

A constant factor that adjusts for intermolecular attractions pulling particles away from container walls, which causes measured real gas pressure to be lower than ideal pressure.

Real Gas Volume Correction ($b$)

A constant factor subtracted from container volume to account for the actual physical volume occupied by gas particles.

Temporary Dipole

A fleeting shift in electron distribution in larger atoms such as xenon that creates transient attractions with neighboring particles.

Permanent Dipole

A constant partial positive and partial negative charge across a polar molecule resulting from differences in electronegativity, driving continuous intermolecular attractions.