Properties of Gases.

This set of flashcards covers key concepts related to the properties of gases, their behaviors, and relevant laws in chemistry.

Characteristics of gases

Physical properties of gases are similar, mainly composed of nonmetallic elements with low molecular masses.

Compressibility

Gases are highly compressible, allowing them to be squeezed into a smaller volume.

Homogeneous mixture

Two or more gases form a homogeneous mixture because their molecules distribute equally.

Pressure

The amount of force applied per unit area; for gases, it arises from molecular collisions.

Atmospheric pressure

The weight of air per unit area, decreasing as altitude increases.

Units of pressure

Common units include Pascal, Torr, ATM, and Kpsi.

Standard atmospheric pressure (STP)

Defined as 1 ATM and a temperature of 273 K.

Boyle's Law

At constant temperature, pressure and volume of a gas are inversely proportional.

Charles' Law

At constant pressure, the volume of gas is directly proportional to its temperature in Kelvin.

Avogadro's Law

Volume of a gas at constant temperature and pressure is directly proportional to the number of moles.

Ideal Gas Law

PV = nRT relates pressure (P), volume (V), number of moles (n), gas constant (R), and temperature (T).

Dalton's Law of Partial Pressures

In a mixture of non-reacting gases, the total pressure is the sum of pressures from each gas.

Mole fraction

Ratio of moles of one substance to total moles in a mixture, used to calculate partial pressures.

Deviation from ideal gas behavior

Occurs at high pressures or low temperatures when gases exhibit intermolecular forces or significant volume.

Gathering gas under conditions

Use PV = nRT to solve for moles, volume, or pressure based on given parameters.

Density of a gas

Can be derived from the ideal gas law as density = (molar mass * P) / (RT).

Characteristics of gases

Physical properties of gases are similar, mainly composed of nonmetallic elements with low molecular masses.

Compressibility

Gases are highly compressible, allowing them to be squeezed into a smaller volume.

Homogeneous mixture

Two or more gases form a homogeneous mixture because their molecules distribute equally.

Pressure

The amount of force applied per unit area; for gases, it arises from molecular collisions.

Atmospheric pressure

The weight of air per unit area, decreasing as altitude increases.

Units of pressure

Common units include Pascal, Torr, ATM, and Kpsi.

Standard atmospheric pressure (STP)

Defined as 1 ATM and a temperature of 273 K.

Boyle's Law

At constant temperature, pressure and volume of a gas are inversely proportional ($P \propto \frac{1}{V}$).

Charles' Law

At constant pressure, the volume of gas is directly proportional to its temperature in Kelvin ($V \propto T$).

Avogadro's Law

Volume of a gas at constant temperature and pressure is directly proportional to the number of moles ($V \propto n$).

Ideal Gas Law

$PV = nRT$ relates pressure ($P$), volume ($V$), number of moles ($n$), gas constant ($R$), and temperature ($T$).

Dalton's Law of Partial Pressures

In a mixture of non-reacting gases, the total pressure is the sum of pressures from each gas ($P<em>{total} = P</em>1 + P_2 + …$).

Mole fraction

Ratio of moles of one substance to total moles in a mixture, used to calculate partial pressures ($X<em>i = \frac{n</em>i}{n_{total}}$).

Deviation from ideal gas behavior

Occurs at high pressures or low temperatures when gases exhibit intermolecular forces or significant molecular volume.

Gathering gas under conditions

Use $PV = nRT$ to solve for moles, volume, or pressure based on given parameters.

Density of a gas

Can be derived from the ideal gas law as $d = \frac{MP}{RT}$, where $M$ is the molar mass.

Gay-Lussac's Law

At constant volume, the pressure of a gas is directly proportional to its absolute temperature ($P \propto T$).

Kinetic Molecular Theory (KMT)

A model describing gases as particles in constant random motion with negligible volume and elastic collisions.

Root-mean-square (rms) speed

The speed of a molecule possessing a kinetic energy identical to the average kinetic energy of the sample: $u_{rms} = \sqrt{\frac{3RT}{M}}$.

Graham's Law of Effusion

The rate of effusion of a gas is inversely proportional to the square root of its molar mass ($\frac{r<em>1}{r</em>2} = \sqrt{\frac{M<em>2}{M</em>1}}$).

Van der Waals Equation

A modified version of the ideal gas law that accounts for non-ideal behavior: $(P + \frac{n^2a}{V^2})(V - nb) = nRT$.

Effusion

The process of a gas escaping through a tiny hole into an evacuated space.

Diffusion

The spread of one substance throughout a second substance or throughout a space.