Gases and Thermodynamics: Kinetic Molecular Theory and Internal Energy

Vocabulary flashcards covering the key terms, formulas, and relationships of Kinetic Molecular Theory, gas work, heat, and internal energy.

Internal Energy ($U$)

The total energy of all gas molecules in a system, calculated as $U = \frac{3}{2}nRT = \frac{3}{2}PV$.

Boltzmann's Constant ($k$)

The constant represented by lowercase $k$ in the formula for the average energy of a single molecule: $K = kT = \frac{1}{2}mv^2$.

Compression

A decrease in volume ($-\Delta \text{volume}$) that results in positive work ($+W$) done to the gas system.

Expansion

An increase in volume ($+\Delta \text{volume}$) that results in negative work ($-W$) done to the gas system.

First Law of Thermodynamics ($\Delta U = Q + W$)

The principle stating that the change in internal energy ($\Delta U$) of a gas system is determined by the heat added or removed ($\pm Q$) and the work done on or by the system ($\pm W$).

Surrogate for Temperature

The product of pressure and volume ($P \cdot V$), which serves as an indicator of temperature when moles of gas are constant.

Kinetic Molecular Theory (KMT)

A framework demonstrating that higher temperature ($T$) directly causes an increase in gas internal energy ($U$) and molecular velocity ($v$).