Ch. 10:Understanding Gases: Properties and Laws in Chemistry

Gas

A phase of matter with fast-moving particles.

Pressure

Force exerted per unit area by gas molecules.

Gas Laws

Relationships between pressure, volume, and temperature.

Ideal Gas Law

PV=nRT; relates pressure, volume, moles, and temperature.

Dalton's Law

Total pressure equals sum of partial pressures.

Kinetic Molecular Theory

Model explaining gas behavior based on particle motion.

Elastic Collisions

No energy loss when gas particles collide.

Average Kinetic Energy

Proportional to the Kelvin temperature of gas.

Boyle's Law

Pressure inversely proportional to volume at constant temperature.

Charles's Law

Volume directly proportional to temperature at constant pressure.

Avogadro's Law

Volume directly proportional to number of moles.

Barometer

Device measuring atmospheric pressure using mercury.

Pressure Imbalance

Difference in pressure causing eardrum to pop.

Gas Particle Motion

Gas particles move randomly and collide elastically.

Volume (V)

Space occupied by gas in a container.

Temperature (T)

Measure of average kinetic energy of gas particles.

Number of Moles (n)

Quantity of gas measured in moles.

Pressure Units

Common units include atm, mmHg, and pascals.

Effusion

Gas escaping through a tiny opening.

Diffusion

Gas spreading out to fill available space.

Pressure Factors

Depends on particle number, volume, and speed.

Gas Mixtures

Homogeneous combinations of different gas types.

Boyle's Law

Volume inversely proportional to pressure at constant temperature.

Charles's Law

Volume directly proportional to temperature at constant pressure.

Kinetic Molecular Theory

Gas particles in constant motion influence pressure.

Avogadro's Law

Volume proportional to number of moles at constant temperature.

Ideal Gas Law

PV = nRT relates pressure, volume, and temperature.

Gas Constant (R)

Constant used in Ideal Gas Law equations.

Pressure (P)

Force exerted per unit area by gas collisions.

Volume (V)

Space occupied by a gas, measured in liters.

Moles (n)

Quantity of gas measured in number of particles.

Standard Conditions

Agreed conditions for reporting gas measurements.

Absolute Temperature

Temperature measured from absolute zero in Kelvin.

Gas Expansion

Increase in gas volume with temperature rise.

Pressure Drop

Decrease in pressure causes gas volume to increase.

Collision Frequency

Rate at which gas particles collide with walls.

Force per Unit Area

Definition of pressure in gas systems.

Volume Calculation

Determining gas volume using pressure and temperature.

Temperature Conversion

Change Celsius to Kelvin for gas law calculations.

Gas Behavior

Describes how gases respond to changes in conditions.

Gas Sample

Specific quantity of gas used in calculations.

Closed Vessel

Container where gas volume and pressure are measured.

Gas Measurement

Quantitative assessment of gas properties under conditions.

Standard Conditions

Conditions for gas measurements: 1 atm, 0°C, 273 K.

Molar Volume

Volume of one mole of gas at STP: 22.4 L.

Gas Density

Density calculated as grams per volume (d = g/V).

Ideal Gas Law

PV = nRT, relates pressure, volume, temperature, moles.

Partial Pressure

Pressure exerted by a single gas in a mixture.

Mole Fraction (χa)

Ratio of moles of component to total moles.

Vapor Pressure

Pressure of water vapor at a given temperature.

Collecting Gases

Gases displace water, causing vapor pressure issues.

Gas Mixture

Combination of different gases, like dry air.

Diatomic Gas

Gas composed of two atoms, e.g., O₂, N₂.

Molar Mass Calculation

Determined using ideal gas law parameters.

Gas Volume at STP

1 mole occupies 22.4 L at standard conditions.

Temperature Conversion

0°C equals 273 K for gas calculations.

Pressure Conversion

1 atm equals 760 torr for pressure measurements.

Density of Gas

Mass per unit volume, crucial for calculations.

Gas Sample Measurement

Volume, temperature, and pressure needed for analysis.

Total Pressure Calculation

Sum of individual gas pressures in a mixture.

Oxygen Collection Experiment

Pressure and volume measured to find gas mass.

Solid CO2 Vaporization

Solid CO2 turns to gas, affecting pressure.

Water Vapor in Gas

Affects total pressure when collecting gases.

Vapor Pressure

Pressure exerted by vapor in equilibrium.

Ideal Gas Law

PV=nRT; relates pressure, volume, temperature, moles.

Stoichiometry

Relationship between reactants and products in reactions.

Nitric Acid Formation

3NO2 + H2O → 2HNO3 + NO reaction.

Hydrogen Gas Collection

240.0 ml of H2 at 30.0 °C and 1.032 atm.

Vapor Pressure of Water

Pressure of water vapor at specific temperature.

Kinetic Energy

Depends on mass and velocity of gas molecules.

Root Mean Square Velocity

Average velocity of gas particles in m/s.

Molecular Speed

Speed of gas molecules related to mass.

Temperature Effect

Higher temperature increases molecular velocity distribution.

Diffusion

Molecules spreading from high to low concentration.

Effusion

Molecules escaping through a small hole.

Graham's Law of Diffusion

Rate ratio of effusion inversely proportional to molar mass.

Real Gases

Do not behave ideally at high pressure, low temperature.

Deviation Due to Pressure

Molar volume increases beyond ideal gas predictions.

Finite Volume of Gas Particles

Real gas volume larger than ideal gas volume.

Deviation Due to Temperature

Pressure lower than ideal gas at low temperatures.

Intermolecular Attractions

Forces between molecules affecting gas behavior.

Van der Waals Equation

Modified ideal gas equation for real gas behavior.

Boyle's Law

Pressure inversely proportional to volume at constant temperature.

Avogadro's Law

Volume directly proportional to moles at constant temperature and pressure.

Dalton's Law of Partial Pressures

Total pressure equals sum of individual gas pressures.