Kopp-Ch 6 from summary Gases and Liquids

Vocabulary flashcards covering gas and liquid properties, temperature scales, heat transfer modes, phase changes, humidity concepts, and key gas laws.

Gas

A state of matter with no fixed shape or volume that can be compressed or expanded and can flow.

Kelvin (K)

SI unit of thermodynamic temperature; absolute scale with 0 K as zero; relation to Celsius: K = C + 273.15.

Celsius (°C)

Temperature scale where water freezes at 0°C and boils at 100°C; relation to Kelvin: C = K − 273.15.

Fahrenheit (°F)

Temperature scale used in some regions; conversion: F = (9/5)C + 32.

Conduction

Heat transfer through direct contact without bulk motion of the medium.

Convection

Heat transfer by bulk movement of a fluid.

Radiation

Heat transfer via electromagnetic waves; does not require a medium.

Evaporation

Vaporization at a liquid surface below the boiling point; energy is drawn from the surroundings, cooling the air.

Vaporization

Phase change from liquid to gas; includes evaporation and boiling.

Boiling

Vaporization that occurs throughout the liquid when the vapor pressure equals ambient pressure.

Surface Tension

Cohesive forces at a liquid surface; increases internal pressure in small drops/bubbles and is inversely related to radius.

Hydrostatic Pressure

Pressure exerted by a liquid due to its height (depth) and weight density.

Buoyant Force

Upward force on submerged objects equal to the weight of displaced liquid (Archimedes’ principle).

Viscosity

Internal friction within a liquid that resists flow.

Capillary Action

Movement of liquid in narrow spaces due to adhesion and cohesion.

Laplace Pressure

Pressure difference across a curved liquid interface due to surface tension; increases with surface tension and decreases with radius (≈2γ/R for a sphere).

Vaporization (repetition)

General term for liquid-to-gas phase change; see Vaporization and Boiling definitions.

Condensation

Gas to liquid phase change; releases heat to surroundings, warming them.

Saturation Vapor Pressure

Maximum vapor pressure of water in air at a given temperature; increases with temperature.

Absolute Humidity

Actual water vapor content in air (mass of water vapor per unit volume).

Relative Humidity (RH)

RH = (actual vapor pressure / saturation vapor pressure) × 100%; cooling increases RH, warming decreases RH at constant content.

Graham’s Law (Diffusion Rate)

Rate of diffusion of a gas is inversely proportional to the square root of its molar mass.

Dalton’s Law of Partial Pressures

Total pressure of a gas mixture equals the sum of its component partial pressures.

Henry’s Law

Amount of gas dissolved in a liquid is proportional to its partial pressure in the gas phase; solubility decreases with higher temperature.

Solubility Coefficient

Proportionality constant relating the amount of dissolved gas to its partial pressure.

Charles’ Law

Gas volume is proportional to absolute temperature at constant pressure (V ∝ T).

Boyle’s Law

Gas volume is inversely proportional to pressure at constant temperature (V ∝ 1/P).

Gay‑Lussac’s Law

Gas pressure is proportional to absolute temperature at constant volume (P ∝ T).

Bernoulli’s Principle

In steady flow, faster flow leads to lower downstream pressure; energy is conserved per unit volume.

Venturi Effect

Pressure drop observed when a fluid passes through a constricted section, illustrating Bernoulli’s principle.

Poiseuille’s Law

Relates pressure drop to viscosity, length, radius, and flow rate for laminar flow in a tube.