Enthalpy change is the heat absorbed or released during a chemical reaction at constant pressure, reflecting the difference in enthalpy between reactants and products. It is a crucial indicator in thermodynamics, determining whether a reaction is endothermic or exothermic and influencing reaction feasibility and spontaneity.

Enthalpy Change

Enthalpy change

heat absorbed

Heat released

A chemical reaction is a process where substances, known as reactants, are transformed into different substances, called products, through the breaking and forming of chemical bonds. This transformation involves changes in energy and is governed by the principles of conservation of mass and energy.

chemical reaction

constant pressure

difference in enthalpy

In a chemical reaction, reactants are the starting substances that undergo transformation, while products are the substances formed as a result of the reaction. Understanding the conversion from reactants to products is essential for predicting the outcome and balancing chemical equations.

reactants and products

crucial indicator

Thermodynamics is the branch of physics that deals with the relationships between heat, work, temperature, and energy. It is fundamental in understanding how energy is transferred in physical systems and the limitations of energy conversion processes.

thermodynamics

An endothermic reaction is a chemical process that absorbs energy from its surroundings, typically in the form of heat, resulting in a cooling effect. These reactions are characterized by a positive change in enthalpy, indicating that the energy required to break bonds in the reactants is greater than the energy released when new bonds form in the products.

Endothermic Reaction

An exothermic reaction is a chemical reaction that releases energy in the form of heat or light, causing the temperature of the surrounding environment to increase. These reactions are characterized by a negative change in enthalpy, indicating that the energy of the products is lower than that of the reactants.

Exothermic Reaction

reaction feasibility

Reaction spontaneity refers to the natural tendency of a chemical reaction to occur without external intervention, determined by the Gibbs free energy change (ΔG) of the system. A negative ΔG indicates a spontaneous reaction, while a positive ΔG suggests non-spontaneity under constant temperature and pressure conditions.

Relevant Degrees

Your Lessons