Exothermic

Definition

Exothermic refers to a chemical reaction or process that releases energy in the form of heat to the surrounding environment. These reactions produce more energy than they consume, resulting in a net release of heat.

5 Must Know Facts For Your Next Test

1. Exothermic reactions release energy to the surroundings, causing the temperature of the environment to increase.
2. The energy released in an exothermic reaction is often used to initiate or drive other chemical processes, such as in combustion reactions.
3. Exothermic processes are typically favored in chemical equilibria, as they contribute to the overall decrease in the system's free energy.
4. The dissolution of many ionic compounds in water is an exothermic process, as the energy released during solvation exceeds the energy required to break apart the crystal lattice.
5. Exothermic reactions are often used in industrial processes, such as the production of ammonia and the combustion of fuels, to generate heat and power.

Review Questions

• Explain how the concept of exothermic reactions relates to the topic of energy basics.
  • Exothermic reactions are fundamental to the concept of energy basics, as they involve the release of energy in the form of heat to the surrounding environment. This energy release is a key aspect of the first law of thermodynamics, which states that energy can be transformed from one form to another but cannot be created or destroyed. Exothermic reactions demonstrate the conversion of chemical energy into thermal energy, highlighting the principles of energy conservation and transformation.
• Describe the role of exothermic processes in the context of calorimetry and enthalpy.
  • Calorimetry is the experimental technique used to measure the heat released or absorbed during a chemical reaction or physical process. Exothermic reactions are central to calorimetry, as the heat released by the reaction can be measured and used to determine the enthalpy change, or the change in the total energy of the system. Enthalpy, a measure of the total energy of a system, is directly affected by exothermic processes, as the energy released contributes to the overall decrease in the system's free energy.
• Analyze how the concept of exothermic processes relates to the topics of dissolution, equilibrium calculations, spontaneity, and free energy.
  • Exothermic processes play a significant role in various chemical concepts. The dissolution of many ionic compounds in water is often an exothermic process, as the energy released during solvation exceeds the energy required to break apart the crystal lattice. In the context of equilibrium calculations, exothermic reactions are typically favored, as they contribute to the overall decrease in the system's free energy. Spontaneity, the natural tendency of a process to occur, is also influenced by exothermic processes, as they are generally more favorable and occur more readily. Finally, the concept of free energy, which combines the energy released or absorbed during a reaction with the system's entropy, is directly impacted by exothermic processes, as the energy release contributes to the overall decrease in the system's free energy.

Related terms

Endothermic: Endothermic reactions are the opposite of exothermic, as they absorb energy from the surroundings in the form of heat to proceed.

Enthalpy: Enthalpy is a measure of the total energy of a system, including the energy released or absorbed during a chemical reaction.

Calorimetry: Calorimetry is the experimental technique used to measure the amount of heat released or absorbed during a chemical reaction or physical process.