An endothermic reaction is one in which the enthalpy H (or internal energy U) of the system increases. Thermal energy from the surrounding environment is often lost by a closed system, which is heat transfer into the system. The melting of ice cubes, for example, is an example of a chemical process. “Endon” means “inside,” and the Greek root “therm,” which means “hot” or “warm” in the sense that a process relies on absorbing heat to develop, was used by Marcellin Berthelot to coin the phrase.
So, an endothermic reaction is one in which the substance’s heat energy is higher while the substance’s heat energy decreases (outside the substance the temperature drops, and the temperature increases inside the substance).
Endothermic Reaction
What is Endothermic Reaction?
Reactions in which heat energy is absorbed by reactants to generate products are known as endothermic reactions. These reactions cool the surrounding environment by lowering the temperature. Thermodynamic processes may also be endothermic.
Breaking a chemistry connection frequently results in the release of energy. Furthermore, power is necessary for the creation of a chemical bond. It is possible to supply/release energy in a variety of ways (such as heat, light, and electricity). An energy shift often occurs as a result of bonds breaking and forming during different processes (state transitions, chemical reactions).
Endothermic Chemical Reactions
The entropy change (S) and absolute temperature T both have a role in determining whether or not a process may occur spontaneously. Gibbs free energy G = H-TS is lower for the products of an exergonic process at a specific temperature than for the reactants, even if the products’ enthalpy is larger. The enthalpy rise H >> 0 in a hypothetical highly endothermic process frequently leads to G = H -T -S > 0, which suggests that the process will not be carried out.
C6H12O6 + 6 H2O → 12 H2 + 6 CO2, ∆r Ho = +627 Kj/mol, ∆r Go = -31 Kj/mol
Endothermic Reactions: Heat is absorbed
An endothermic reaction or physical change is one in which the system takes in heat from the environment rather than generating it. The temperature of the surrounding environment drops as a result of the system gaining heat from the environment. The letter q denotes the amount of heat required for a certain procedure. Endothermic processes have a positive q sign, indicating that the system is becoming hotter as it runs.
Exothermic Reactions: Heat is Released
Exothermic reactions are those in which heat is found in the environment through a chemical reaction or physical change. To keep the system from overheating, the temperature of the surroundings rises. The exothermic process, on the other hand, results in the release of energy rather than the absorption of energy. This amount of energy is frequently more than the sum of the energies of the reactants themselves. When a match is struck, more releases energy from the resulting flame than is contained inside the matchstick itself. Exothermic reactions release energy into the surrounding environment. such that enthalpy (a unit of energy) changes.
Endothermic vs Exothermic Reactions
| Endothermic Reactions | Exothermic Reactions |
| A chemical reaction is called an endothermic reaction when the reactants absorb heat energy from the surrounding environment to produce products of their own making. | An exothermic process is one in which energy is discharged in the form of light or heat. |
| The ambient energy is lost in the reaction. | The system dissipates its stored energy into the surrounding environment. |
| Heat is a form of energy which is a by-product. | Heat, electricity, light, or sound are all ways that energy is given off. |
Endothermic Process vs Endothermic Reaction
The human body uses the fact that evaporation gives off heat to cool itself. This is done by letting your body sweat. The heat from the skin is lost by the sweat on the skin’s surface, which then evaporates and cools the body.
But sweating is not a process that releases heat. In chemical reactions, existing chemical bonds can be broken, new bonds can be made, or both can happen. When sweat evaporates, there are no chemical changes, but there is a change in the way the sweat looks (from liquid to vapour). So, people say that evaporation is a physical endothermic process, not a chemical endothermic reaction.
An endothermic process takes heat from its surroundings. Because of this, all reactions that produce heat are endothermic processes. But it’s not the other way around. Many endothermic processes involve changes in the way things look instead of changes in the way things work.
Energy Level Diagram of Endothermic Reaction
The reactants have less energy than the products in an endothermic reaction. So, the energy of the reactants is farther away from the energy of the transition state. This means that the activation energy for endothermic reactions is higher than it is for exothermic reactions. An endothermic reaction occurs when the potential energy of the product is greater than the potential energy of the reactants. The energy absorbed by the system during the chemical reaction is accounted for by this void in the potential energy.
FAQs on Endothermic Reactions
Question 1:State some of the examples of endothermic reactions.
Answer:Some of the examples of endothermic reactions are:
- Ammonium chloride may be dissolved in water.
- The process of breaking down alkanes
- Stars produce elements heavier than nickel by nuclear fusion.
- The process of evaporating water
- Ice that has melted
Question 2:Explain the energy conversation taking place in an endothermic reaction.
Answer:There’s a lot of movement here. The heat that is absorbed in the endothermic process is transformed into chemical energy. It’s important to remember that temperature is a measure of heat, not energy.
