Thermochemistry Flashcards

Flashcards for Thermochemistry Review

Energy

Capacity to do work or transfer heat.

System

The focus of study in thermodynamics.

Surroundings

Everything else outside the system in thermodynamics.

Internal Energy (E)

Sum of all kinetic & potential energy in a system (E = KE + PE).

DeltaE

Change in internal energy (Efinal - Einitial).

Heat (q)

Energy transferred due to temperature difference.

Work (w)

Energy transferred when a force causes displacement.

Enthalpy (H)

H = E + PV, DeltaH = q_p at constant pressure.

Exothermic

Reaction that releases heat (DeltaH < 0).

Endothermic

Reaction that absorbs heat (DeltaH > 0).

Calorimetry

Technique to measure heat transfer during a chemical or physical change.

Hess's Law

DeltaH is additive over reaction steps.

Standard Enthalpy of Formation (DeltaHf degrees)

Heat change when 1 mol of compound forms from elements in standard states.

Specific Heat Capacity (c)

The amount of heat required to raise the temperature of 1 gram of a substance by 1 degree Celsius.

State Function

A property that depends only on the initial and final states, not the path taken (e.g., internal energy).

Joule (J)

The SI unit of energy.

First Law of Thermodynamics

Energy cannot be created or destroyed, only transferred or transformed.