Gas Laws and Properties of Gases

This set of flashcards covers key vocabulary and concepts related to gas laws and properties of gases, including definitions and explanations to aid in understanding and study.

Pressure

The magnitude of the force per unit area exerted by gas molecules on the walls of their container.

Pascal (Pa)

SI unit of pressure, equivalent to a force of one Newton acting on an area of one square meter.

Atmospheric pressure

Pressure exerted by the weight of air in the atmosphere, measured at sea level.

Barometer

Instrument used to measure atmospheric pressure, typically consisting of a column of mercury.

Mercury

A liquid metal used in barometers for measuring pressure due to its density and low vapor pressure.

Boyle's Law

The volume of a fixed mass of gas is inversely proportional to its pressure at constant temperature.

Charles’ Law

The volume of a fixed amount of gas is directly proportional to its absolute temperature at constant pressure.

Ideal Gas Law

Equation of state for a gas, represented as PV=nRT, where P is pressure, V is volume, n is number of moles, R is the gas constant, and T is temperature.

Dalton's Law of Partial Pressures

The total pressure of a mixture of gases is equal to the sum of the partial pressures of its individual gases.

Kinetic Molecular Theory

A theory that explains the behavior of gases based on the motion and collisions of their molecules.

Avogadro's Law

At the same temperature and pressure, equal volumes of gases contain equal numbers of molecules.

Torr

A unit of pressure defined as 1/760 of an atmosphere, often used in measuring gas pressures.

Millimeters of Mercury (mm Hg)

A unit of pressure defined as the pressure exerted by a column of mercury 1 mm high.

Gay-Lussac’s Law

The pressure of a fixed mass of gas at constant volume is directly proportional to its absolute temperature.

Gas constant (R)

A constant used in the ideal gas equation, with values dependent on the units used for P, V, and T.

Standard Temperature and Pressure (STP)

Defined as 0°C (273.15 K) and 1 atm pressure, used for gas calculations.

Manometer

An instrument used to measure the pressure of a gas in a closed container relative to atmospheric pressure.

Combined Gas Law

An expression that combines Boyle's Law, Charles' Law, and Gay-Lussac's Law into a single equation: P1V1/T1 = P2V2/T2.

Effusion

The process by which gas particles pass through a tiny opening into a vacuum.

Diffusion

The process by which gas particles spread out evenly in a container.

Volume Correction

Adjustment to account for the volume occupied by gas molecules in the van der Waals equation.

Pressure Correction

Adjustment to the ideal gas equation to account for the attractive forces between molecules in the van der Waals equation.

Newton

The SI unit of force; defined as the force necessary to accelerate a mass of one kilogram by one meter per second squared.

Density of a gas

The mass of a gas per unit volume, often expressed in grams per liter (g/L) at specific conditions.

Graham’s Law

Law stating that the rate of effusion of a gas is inversely proportional to the square root of its molar mass.

Absolute Zero

The theoretical lowest temperature possible, at which molecular motion comes to a complete stop, 0 K or -273.15 °C.

Mercury Column Height

The height of the mercury column in a barometer, corresponding to the atmospheric pressure.

Pound per square inch (psi)

An English unit of pressure, defined as the pressure exerted by one pound-force on one square inch.

Kelvin scale

An absolute temperature scale used in scientific contexts, starting from absolute zero.

Elastic Collision

A collision in which there is no net loss of kinetic energy in the system.

Mole Fraction

Ratio of the number of moles of a component to the total number of moles of all components in a mixture.

Partial Pressure

The pressure a single gas in a mixture would exert if it occupied the entire volume alone.

Inverse Relationship

A relationship in which one quantity increases while the other decreases.

Direct Relationship

A relationship where both quantities increase or decrease together.

Pressure Units

Different measures of pressure, including atm, Pa, torr, mm Hg, psi, and bar.

Atmosphere (atm)

A unit of pressure defined as 101,325 pascals.

Molecular Weight

The mass of one mole of a substance, usually expressed in grams per mole (g/mol).

Thermodynamic Variable

A measurable property of a system, such as pressure, volume, temperature, or internal energy.

Gaseous State

The state of matter characterized by having no fixed shape or volume and being able to expand to fill its container.

High Altitude Pressure

Lower atmospheric pressure experienced at high elevations due to less air above pressing down.

Pressure Exertion

The result of gas molecules colliding with the walls of a container, causing a force distributed over an area.

Volume Expansion

The increase in volume of a gas as it is heated at constant pressure.

Gas Compression

The decrease in volume of a gas when pressure is applied, allowing the gas to occupy less space.

Boyle's Law

For a given mass of gas at constant temperature, the volume of the gas is inversely proportional to the pressure. Formula: P1 V1 = P2 V2.

Charles's Law

For a given mass of gas at constant pressure, the volume of the gas is directly proportional to its absolute temperature. Formula: \frac{V1}{T1} = \frac{V2}{T2}.

Avogadro's Law

At the same temperature and pressure, equal volumes of gases contain an equal number of molecules. Formula: \frac{V1}{n1} = \frac{V2}{n2}.

Ideal Gas Law

The relationship among pressure, volume, temperature, and number of moles of a gas is described by the Ideal Gas Law. Formula: PV = nRT.

Combined Gas Law

Combines Boyle's, Charles's, and Avogadro's laws. Formula: \frac{P1 V1}{T1} = \frac{P2 V2}{T2}.

Gay-Lussac's Law

At constant volume, the pressure of a gas is directly proportional to its absolute temperature. Formula: \frac{P1}{T1} = \frac{P2}{T2}.

How many Pascals are in 1 atm?

1 atm = 101.325 Pa.

How many torr are in 1 atm?

1 atm = 760 torr.

How many mm Hg are in 1 atm?

1 atm = 760 mm Hg.

How many bars are in 1 atm?

1 atm = 1.01325 bar.

How many inches of mercury are in 1 atm?

1 atm = 29.92 in Hg.

How many psi are in 1 atm?

1 atm = 14.696 psi.