Chemical Energetics Review

These flashcards cover the fundamental concepts related to chemical energetics, focusing on enthalpy changes, reaction types, and energy transformations.

Enthalpy Change (ΔH)

The heat content change in a chemical reaction, indicating whether the reaction is exothermic (negative ΔH) or endothermic (positive ΔH).

Exothermic Reaction

A reaction that releases energy (heat, light, etc.) to the surroundings, resulting in a negative enthalpy change (ΔH < 0).

Endothermic Reaction

A reaction that absorbs energy from the surroundings, leading to a positive enthalpy change (ΔH > 0).

Activation Energy

The minimum energy required for reactants to collide and form products in a chemical reaction.

Bond Breaking

An endothermic process where energy is absorbed to break chemical bonds in reactants.

Bond Formation

An exothermic process where energy is released when new bonds are formed in products.

Energy Profile Diagram

A graphical representation showing the energy changes during a reaction, including activation energy and enthalpy change.

Thermochemical Equation

An equation that shows the reactants, products, and the associated enthalpy change of a reaction.

Energy Change (kJ/mol)

The amount of energy involved in a reaction, measured in kilojoules per mole.

Combustion

An exothermic reaction where a substance reacts with oxygen to produce energy, carbon dioxide, and water.

Dissolving Ammonium Chloride

An endothermic process that absorbs heat from its surroundings, causing a temperature decrease.

Bond Energy

The amount of energy required to break a bond between two atoms, indicative of bond strength.

Overall Enthalpy Change

Determined by comparing the energy absorbed during bond breaking to the energy released during bond formation.

Chemical Energy

Energy stored in the bonds of chemical compounds, which can be released or absorbed during a reaction.

Fuels

Substances that burn easily in air to release energy; examples include wood, coal, natural gas, and hydrogen.

Electrolysis

A process that uses electrical energy to break down compounds, often used to obtain hydrogen.

Photosynthesis

An endothermic process where light energy is converted into chemical energy in plants.