Chemistry 30: Thermochemical Changes

These flashcards cover key vocabulary terms and concepts related to thermochemical changes, including thermochemistry, energy changes in reactions, calorimetry, and relevant laws.

Thermochemistry

The study of energy changes in a chemical system during a chemical reaction.

Exothermic Reaction

A reaction that releases energy, causing an increase in the temperature of the surroundings.

Endothermic Reaction

A reaction that absorbs energy, causing a decrease in the temperature of the surroundings.

Calorimetry

The process of measuring the quantity of heat transferred during a chemical reaction.

First Law of Thermodynamics

Energy cannot be created or destroyed, only converted from one form to another.

ΔH

The change in enthalpy, or heat content, of a system during a chemical reaction.

Enthalpy Change (ΔH)

The difference between the enthalpy of the products and the reactants at constant pressure.

Potential Energy

Stored energy in chemical bonds, which can change when bonds are broken or formed.

Activation Energy

The minimum energy required for reactants to collide with sufficient energy to react.

Hess's Law

The principle stating that the total enthalpy change for a reaction is the sum of the enthalpy changes for the individual steps of the reaction.

Molar Enthalpy of Reaction

The enthalpy change in a chemical reaction per mole of a specific chemical in a system at constant pressure.

Chemical Potential Energy Diagram

A graphical representation showing the potential energy of the reactants and products during a chemical reaction.

Kinetic Energy

The energy of motion; in a chemical context, related to the movement of molecules.

Hydrocarbon Combustion

An exothermic reaction where hydrocarbons react with oxygen to produce carbon dioxide and water, releasing energy.

Photosynthesis

An endothermic reaction in which plants convert sunlight energy, carbon dioxide, and water into glucose and oxygen.

Cellular Respiration

An exothermic reaction where glucose and oxygen are converted into carbon dioxide, water, and energy.

Specific Heat Capacity (c)

The amount of energy required to raise the temperature of one gram of a substance by one degree Celsius.

Thermal Energy (Q)

The total kinetic energy of all the particles in a substance.

Energy Transfer

The process of energy moving from one system or substance to another.