Thermodynamics and Calorimetry Lecture Review

Vocabulary flashcards covering key concepts from the lecture on thermodynamics, work, state functions, and calorimetry.

Work (thermodynamics)

The energy transfer when a gas expands or contracts against an external pressure, calculated as work = -p *
delta v.

Constant External Pressure

The condition under which work against a gas volume change is often calculated, where the outside pressure remains steady.

Liter Atmosphere

A unit of work or energy, convertible to Joules using the factor 101.3 Joules = 1 liter atmosphere.

State Function

A property of a system that depends only on its initial and final states, not on the path taken to reach those states (e.g., energy, pressure, volume, temperature).

First Law of Thermodynamics

States that energy can neither be created nor destroyed, only converted from one form to another; delta e system +
delta e surroundings = 0.

Exothermic Reaction

A chemical reaction where heat is released from the system into the surroundings, resulting in a negative change in enthalpy (delta h).

Endothermic Reaction

A chemical reaction where energy (heat) is absorbed by the system from the surroundings, resulting in a positive change in enthalpy (delta h).

Internal Energy (delta E)

The total energy contained within a thermodynamic system, calculated as the sum of heat (q) and work (w) exchanged with the surroundings (delta e system = q + w).

Sign Convention (q, w,
delta E)

A positive value indicates energy is being added to or done on the system; a negative value indicates energy is leaving or being done by the system.

Bomb Calorimeter

A sealed vessel submerged in water, used for constant volume calorimetry to measure the change in internal energy (
delta e) of a reaction.

Constant Volume Calorimetry

A method of measuring the change in internal energy (
delta e) of a reaction, typically in an isolated system where no heat enters or leaves, meaning q system = 0 and q bomb = -q reaction.

Enthalpy (delta H)

The heat exchanged in a reaction at constant pressure; negative for exothermic reactions, positive for endothermic reactions.

Coffee Cup Calorimeter

A simple device used for constant pressure calorimetry to measure the heat change (
q or
delta h) of a reaction by observing the temperature change in a solution.

Heat of Neutralization

The change in enthalpy that occurs when an acid and a base react to form one mole of water.