5 - Chemistry Energetics

Exothermic reaction

A reaction that transfers thermal energy to the surroundings, leading to an increase in temperature.

Endothermic reaction

A reaction that takes in thermal energy from the surroundings, leading to a decrease in temperature.

Breaking bonds

An endothermic process where more energy is required to break bonds than is released when the bonds are broken.

Making bonds

An exothermic process where more energy is released in forming bonds than is absorbed to break them.

Activation energy

The minimum energy that colliding particles must have in order to react.

Enthalpy change (ΔH)

The difference between the energy of reactants and products, indicating the energy change during a chemical reaction.

Negative ΔH

Indicates that the energy of products is less than that of reactants, suggesting the reaction is exothermic.

Positive ΔH

Indicates that the energy of products is greater than that of reactants, suggesting the reaction is endothermic.

Common examples of exothermic reactions

Combustion reactions, neutralization reactions, and most oxidation reactions.

Chemical energetics

The study of energy changes in chemical reactions, including exothermic and endothermic processes.