Kinetic Theory of Gases (KTG) and Gas Laws Review

Comprehensive practice flashcards covering Gas Laws, Kinetic Theory of Gases postulates, molecular speeds, degrees of freedom, and specific heat capacities based on the lecture notes.

Boyle's Law

A gas law stating that For a fixed mass of gas, the product of pressure and volume remains constant at a constant temperature; it holds for an ideal gas during isothermal changes.

Ideal Gas Behavior

A condition where real gases act as ideal gases, which occurs specifically at high temperature and low pressure.

Universal Gas Constant (R)

The proportionality constant in the ideal gas equation $PV = nRT$, with an S.I. unit of $J\,mol^{-1}\,K^{-1}$.

Kinetic Theory Postulate (Molecules)

The assumption that molecules of a gas behave like perfectly elastic rigid spheres.

Absolute Zero

The theoretical temperature at which the pressure of a gas becomes zero.

Critical Point

The temperature below which a gas must be cooled before it can be liquified by pressure alone.

Triple Point

The specific condition of temperature and pressure where a substance can coexist in equilibrium in solid, liquid, and gas phases.

Mean Free Path

The average distance a molecule travels between collisions; it is inversely proportional to the square of the molecular diameter ($d^{-2}$).

Van der Waals Constant 'a'

A parameter in the van der Waals equation representing intermolecular forces of attraction; its dimensions are $[M L^5 T^{-2}]$.

Van der Waals Constant 'b'

A parameter in the van der Waals equation representing the correction for the finite volume occupied by the gas molecules.

Pascal's Law

A law stating that the effect of pressure applied to any portion of a fluid is transmitted equally in all directions throughout the fluid.

Specific Gas Constant

The gas constant calculated per unit mass of a gas, often used in equations involving density ($\rho$) and pressure ($P$).

Boltzmann Constant ($k$)

A physical constant that relates the average kinetic energy of particles in a gas with the temperature; the density of an ideal gas can be expressed as $\rho = \frac{Pm}{kT}$.

Dalton's Law of Partial Pressure

The principle stating that the total pressure of a mixture of non-reacting gases is the sum of the individual pressures of each gas component.

Root Mean Square (R.M.S.) Velocity

The square root of the arithmetic mean of the squares of the speeds of the molecules, given by the expression $V_{rms} = \sqrt{\frac{3RT}{M}}$.

Average Speed ($v_{av}$)

The average of the magnitudes of the velocities of molecules in a gas; it is proportional to the square root of the absolute temperature ($\sqrt{T}$).

Most Probable Speed ($v_{mp}$)

The speed possessed by the largest number of molecules in a gas at a given temperature.

Degrees of Freedom ($f$)

The number of independent coordinates required to describe the position and orientation of a molecule; for a monoatomic gas it is 3, and for a diatomic gas it is 5.

Ratio of Specific Heats ($\gamma$)

The ratio of molar specific heat at constant pressure to molar specific heat at constant volume ($C_P/C_V$), defined by the formula $\gamma = 1 + \frac{2}{f}$.

Molar Specific Heat at Constant Volume ($C_V$)

The amount of heat required to raise the temperature of one mole of a gas by one degree while volume remains constant; for a monoatomic gas, $C_V = \frac{3}{2}R$.

Internal Energy ($U$)

The total energy contained within a system; for an ideal gas, it depends only on the absolute temperature ($T$).

Elastic Collision

A collision between gas molecules in which both momentum and kinetic energy are conserved, meaning no kinetic energy is lost.

Pressure of Gas (Kinetic Energy Relation)

The pressure exerted by a gas is related to its average kinetic energy per unit volume ($E$) by the equation $P = \frac{2}{3}E$.

Vapour vs. Gas

A substance is termed a gas when it is above its critical temperature; below that temperature, it is considered a vapour and can be liquefied by pressure.