Energy is conserved in chemical reactions, so the total amount of energy in the universe at the end of a reaction is the same as it was before the reaction.

The statement you provided reflects the principle of the conservation of energy, which is a fundamental concept in chemistry and physics. In the context of chemical reactions, this principle asserts that energy cannot be created or destroyed; it can only be transformed from one form to another.

In chemical processes, reactants undergo transformations to form products, and during this process, the energy associated with the bonds within molecules is either absorbed or released. This energy change can manifest as heat, light, or work, contributing to the overall energy exchange in the system.

For instance, in an exothermic reaction, energy is released into the surroundings, usually in the form of heat, while in an endothermic reaction, energy must be absorbed from the surroundings for the reaction to proceed.

This principle is crucial for understanding thermodynamics in chemical reactions, helping to predict the behavior of substances as they undergo transformations. Overall, it underscores the importance of energy flows and balances in both closed and open systems.