Thermal Chemistry Overview

These flashcards cover key vocabulary and concepts discussed in the thermal chemistry lecture, focusing on enthalpy, reaction types, and fundamental principles of thermodynamics.

Enthalpy (H)

The heat evolved in a reaction at constant pressure.

Delta (Δ)

A Greek letter used to denote change, indicating initial and final states.

State Function

A property that depends only on the current state of the system and not on the path taken to reach that state.

Exothermic Reaction

A chemical reaction that releases heat, characterized by a negative delta H (ΔH).

Endothermic Reaction

A chemical reaction that absorbs heat, characterized by a positive delta H (ΔH).

Hess's Law

The enthalpy change for a stepwise process is equal to the sum of the enthalpy changes for the individual steps.

Standard State Conditions

Defined conditions for measurements including 1 atmosphere pressure and specified temperatures.

Allotropes

Different forms of the same element, such as graphite and diamond for carbon.

Heat of Formation

The amount of heat energy released or absorbed when one mole of a compound is formed from its elements in their standard states.

Chemical Heat Pack

A pack that releases heat when a chemical reaction, such as oxidation, occurs inside.

Cold Pack

A pack that absorbs heat from its surroundings, typically used for injuries.

Reaction Stoichiometry

The relationship between the quantities of reactants and products in a chemical reaction.

Molar Concentration

Amount of solute per liter of solution, standard state concentration is defined as one molar.

ΔH

The symbol used to represent the enthalpy change in a reaction.

Math Intensity in Thermal Chemistry

The use of mathematical calculations and formulas to solve thermodynamic problems.

Chemical Reaction Equation

An expression that represents the conversion of reactants to products with associated energy changes.

Thermochemistry

The study of heat changes during chemical reactions.

Oxidation

The process where a substance loses electrons, associated with an increase in oxidation state.

Calorimeter

An instrument used to measure the amount of heat involved in a chemical reaction.

Negative Delta H (ΔH)

Indicates that the reaction releases heat to the surroundings.

Positive Delta H (ΔH)

Indicates that the reaction absorbs heat from the surroundings.

Combustion Reaction

A reaction where a substance combines with oxygen to produce heat and light.