Thermochemistry and Energy Change in Chemical Reactions

Thermochemistry is a branch of ______ that focuses on the energy changes during chemical reactions

The Law of Conservation of Energy states that energy is neither created nor ______ in a system

Energy change refers to the movement of energy within a system, whether the system is gaining or ______ energy

Various processes that can result in energy change include chemical reactions, phase changes, mechanical work, electrical circuits, and ______ processes

A chemical reaction occurs when reactants change into products with new properties through the rearrangement of atoms in molecules, often resulting in an ______ change

Initiation During this stage, atoms or molecules interact before breaking up and recombining to form new products. These interactions may be due to the formation of free radicals in the reactants or a ______ used to trigger the reaction.

After successful initiation, the number of reactive particles increases exponentially until the available reactants are depleted. This stage is known as ______.

After the available reactants have been depleted, the reaction ends and leaves behind products. This final stage is called ______.

An exothermic reaction is a chemical reaction that releases energy to its surroundings, typically in the form of heat, light, or both. The name originates from the Greek words 'exo' meaning 'out' and 'thermos' meaning 'heat,' literally translating to 'outward ______.'

The defining characteristic of exothermic reactions is the negative change in enthalpy (ΔH). Enthalpy represents the system's total energy, so a negative ΔH signifies energy released to the surroundings. In exothermic reactions, the energy is released from the bonds between atoms to form new bonds, resulting in ______ being produced.