Gas Laws, Stoichiometry, and Kinetic Molecular Theory

Vocabulary flashcards covering gas stoichiometry, Dalton's law of partial pressures, the five postulates of Kinetic Molecular Theory (KMT), classical gas laws, and the principles of molecular speed, diffusion, and effusion.

Limiting Reactant

The reactant in a chemical reaction that is completely consumed first, yielding the least amount of product and determining the maximum extent of the reaction.

Dalton's Law of Partial Pressure

A gas law stating that the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures exerted by each individual gas in the mixture.

Postulate 1 of Kinetic Molecular Theory

The postulate stating that gases consist of small molecules that are in continuous, random motion.

Postulate 2 of Kinetic Molecular Theory

The postulate stating that the physical volume occupied by the gas molecules themselves is negligible compared to the total volume occupied by the gas (accounting for less than a tenth of a percent of the space).

Postulate 3 of Kinetic Molecular Theory

The postulate stating that attractive and repulsive forces between gas molecules are negligible except during collisions.

Postulate 4 of Kinetic Molecular Theory

The postulate stating that collisions between gas molecules or between gas molecules and the container walls are perfectly elastic, meaning no kinetic energy is lost.

Postulate 5 of Kinetic Molecular Theory

The postulate stating that the average kinetic energy of gas molecules is directly proportional to the absolute temperature of the gas.

Boyle's Law

The gas law stating that pressure and volume are inversely proportional; compressing a gas into a smaller volume increases the collision frequency of molecules with the container walls, thereby increasing pressure.

Charles's Law

The gas law stating that volume is directly proportional to temperature; heating increases particle speeds and collision force against container walls, causing flexible containers to expand under constant exterior pressure.

Avogadro's Law

The gas law stating that gas volume is directly proportional to the number of moles of gas present, independent of the chemical identity of the particles.

Molar Volume of an Ideal Gas at STP

The volume occupied by exactly $1.00\,\text{mole}$ of any gas at standard temperature and pressure ($273\,\text{K}$ and $1\,\text{atm}$), which is equal to $22.4\,\text{L}$.

Root-Mean-Square Speed ($v_{\text{rms}}$)

The measure of the average speed of particles in a gas at a specific temperature, given by the expression $\sqrt{\frac{3RT}{M}}$, where speed is directly proportional to the square root of temperature and inversely proportional to the square root of molar mass.

Diffusion

The process by which different gas species intermingle as a result of their random molecular motion, ultimately forming an evenly distributed mixture.

Effusion

The escape of gas molecules from a container into an evacuated space or region through a tiny pinhole.

Rate of Effusion Ratio

The mathematical ratio comparing the effusion rates of two gases, given by $\sqrt{\frac{M_2}{M_1}}$, demonstrating that lighter gas molecules travel faster and escape a container more rapidly than heavier ones.