Chapter 11: Gases Practice Flashcards

This set of vocabulary flashcards covers the fundamental concepts, laws, and units related to the study of gases as presented in Chapter 11, including the simple gas laws, Ideal Gas Law, and Kinetic Molecular Theory.

Gas

A phase of matter composed of particles that are moving randomly and very fast in their container(s), moving in straight lines until they collide with a surface or another particle.

Pressure

The force exerted per unit area by gas molecules as they strike the surfaces around them ($Pressure = \frac{force}{area}$).

Millimeter of mercury (mmHg)

A common unit of pressure where $760\,mmHg = 1\,atm$.

Torr

A unit of pressure that is the same as a millimeter of mercury, where $1\,torr = 1\,mmHg$.

Atmosphere (atm)

A unit of pressure where $1\,atm = 760\,torr$ or $760\,mmHg$. It is the unit typically used for pressure ($P$) in gas law calculations.

Kelvin (K)

The unit of temperature ($T$) used in gas law calculations, where $K = \text{Celsius } T + 273$.

Boyle’s Law

A simple gas law stating that the volume of a gas is inversely proportional to its pressure ($P_1 \times V_1 = P_2 \times V_2$) when temperature and the amount of gas are held constant.

Charles’s Law

A simple gas law stating that the volume of a fixed amount of gas at constant pressure increases linearly with increasing temperature in kelvins ($\frac{V_1}{T_1} = \frac{V_2}{T_2}$).

Avogadro’s Law

A simple gas law stating that volume is directly proportional to the number of gas molecules when pressure and temperature are held constant ($\frac{V_1}{n_1} = \frac{V_2}{n_2}$).

Ideal Gas Law

The combination of simple gas laws expressed as $PV = nRT$, where $P$ is pressure in atm, $V$ is volume in liters, $n$ is moles, $R$ is the ideal gas law constant, and $T$ is temperature in kelvins.

Ideal gas law constant (R)

The constant value used in the ideal gas law, equal to $0.0821$.

Standard conditions (STP)

A set of conditions agreed upon by chemists for reporting measurements: Standard pressure = $1\,atm$, Standard temperature = $273\,K$ ($0\,^\circ C$), Standard amount = $1\,mol$, and Standard volume = $22.4\,L$.

Molar volume

The volume occupied by one mole of a substance at STP ($T = 273\,K$ and $P = 1\,atm$), which is $22.4\,L$ for an ideal gas.

Density of a gas

The ratio of mass to volume, generally given in units of $g/L$. At STP, it is calculated as $\frac{\text{molar mass}}{22.4\,L/mol}$.

Dalton’s Law

States that the total pressure of a gas mixture is the sum of the partial pressures ($P_{total} = P_a + P_b + P_c + \dots$).

Partial pressure

The pressure of a single gas in a mixture of gases, which can be determined if the fraction of the mixture or the specific moles in a given volume and temperature are known.

Kinetic molecular theory

A model for gas behavior where gas is a collection of particles in constant motion with negligible attractions and whose average kinetic energy is directly proportional to Kelvin temperature.

Elastic collision

A collision where particles may exchange energy but there is no overall loss of energy; any kinetic energy lost by one particle is completely gained by the other.