The endothermic reaction is defined as a chemical reaction that is generated by the transformation or change of two or more substances into different ones. When this transformation is generated , it produces as a consequence the consumption of caloric energy where the products obtained have a greater amount of energy levels than at the beginning.
In this sense, it can be formulated as follows: given an enthalpy (H), a perennial endothermic reaction will have an enthalpy differentiation (ΔH) greater than zero (ΔH> 0). We must remember that when we refer to enthalpy we refer to the energy variables that are generated between a certain thermodynamic system and its environment.
We see this reaction commonly reflected in the ice and cooling chemical industries , this is because this reaction is only possible in controlled environments.
Examples of endothermic reaction
- Production of ozone in the atmosphere: it is generated as a result of the ultraviolet radiation emitted by the sun while the oxygen atoms are converted into ozone and absorb during the process, the radiation emitted by the sun.
- Hydrolysis of water: in order to separate the oxygen from the hydrogen of which water is composed, electrical energy is incorporated. In this sense, both atoms respond to the poles, thus breaking the molecular bond that held them together.
- Photosynthesis: it is the nutrition process of plants where several chemical factors intervene that are responsible for decomposing carbon dioxide in the environment in the presence of sunlight and water.
- Obtaining iron sulfide: it is achieved through the creation of hydrogen sulfide in combination with the metal. The result of this combination is passed through a heat process either by burner or cauldron. This heat to which the combination is exposed is what is required for the desired reaction and result to be given.
Endothermic reactions in chemical compounds
- Iron Sulfide: Fe + S + energy → FeS
- Nitrous Oxide: 2 N2 + O2 + energy → 2 N2O
- Ozone: 3O2 + energy (ultraviolet light) → 2O3
- Chromium oxide: (NH4) 2Cr2O7 + energy → N2 + 4 H2O + Cr2O3
- Barium Nitrate: Ba (OH) 2 · 8H2O + 2NH4NO3 + energy → Ba (NO3) 2 + 2NH3 + 10H2O
- Photosynthesis: 6 H2O + 6 CO2 + energy (light) → C6H12O6 + 6 O2