20 Examples of Chemical Phenomena


The chemical phenomena (or chemical reactions) are those phenomena in which changes occur in matter, and new substances called “products” are formed, and others called “reactive” are decomposed. For example: wood rot, paper burning, composting.

chemical reactions can be spontaneous (reactions that occur without the need for energy or catalysts) or not spontaneous (reactions that need the input of energy, catalysts or some external intervention for them to occur). Many times, for a reaction to occur, it is necessary for the reagents to have a specific temperature, a certain pH, a set pressure value, etc.

It may also be essential to control the speed at which chemical reactions occur. Catalysts are substances that are added to a chemical reaction to increase its rate, while inhibitors are substances that slow down chemical reactions. Other factors that affect the rate of a chemical reaction are temperature, pressure, concentration of reactants, and the nature of the reaction itself.

Types of chemical phenomena

Chemical reactions can be:

inorganic reactions. Inorganic compounds are involved and can be classified according to:

  • The direction in which the reaction occurs.
    • reversible reactions. They go both ways, so the products can break down and re-form the reactants.
      chemical phenomena
    • irreversible reactions. They only happen one way.
      chemical phenomena
  • The type of particle that reacts.
    • Acid-base reactions. H ion transfer occurs+.
      chemical phenomena
    • Oxidation-reduction reactions. One of the reactants is oxidized (increases its oxidation number), while the other is reduced (decreases its oxidation number). Electron transfer occurs in these reactions.
      chemical phenomena
  • The reaction speed.
    • Quick reactions. They happen in a very short time.
      chemical phenomena
    • Slow reactions. They take a long time to complete.
      chemical phenomena
  • The form of energy it emits or absorbs.
    • Exothermic reactions. As they occur, they release heat.
      chemical phenomena
    • Endothermic reactions. As they occur, they absorb heat.
      chemical phenomena
    • Exoluminous reactions. When they occur, they emit light.
      chemical phenomena
    • endoluminous reactions. To occur, they need light.
      chemical phenomena
  • The type of transformation.
    • Synthesis or addition reactions. Two substances combine to form a new substance.
      chemical phenomena
    • Decomposition reactions. One or more substances are broken down into their simplest constituents.
      chemical phenomena
    • Displacement or substitution reactions. One element or compound replaces another in a compound, releasing it.
      chemical phenomena
    • Double substitution reactions. Two compounds exchange elements or compounds at the same time.
      chemical phenomena

Organic reactions. They are reactions involving organic compounds. They have many classifications based on the type of organic compound that reacts and the type of reaction that it undergoes. Some examples are:

  • Halogenation of alkanes. A hydrogen of an alkane is replaced by a halogen.
    chemical phenomena
  • alkane combustion. An alkane reacts with oxygen to generate carbon dioxide and water, if combustion is complete.
    chemical phenomena
  • Halogenation of alkenes. One or both hydrogens of the carbons that are involved in the double bond are replaced by halogens.
    chemical phenomena
  • Hydrogenation of alkenes. Hydrogens are added to the carbons involved in the double bond to form the corresponding alkane.
    chemical phenomena

Importance of chemical phenomena

Many chemical phenomena sustain life of living things, such as digestion in humans and animals, photosynthesis in plants, and respiration in both.

Another very important chemical process, especially in the life of microorganisms, is fermentation, which is usually used in the manufacture of foods such as cheeses, yogurts, wines and beers.

all the increase and the developing of a living being involves chemical reactions that occur in it, sometimes stimulated by certain environmental conditions.

Examples of chemical phenomena

Around us there are numerous cases of chemical phenomena or processes that include:

  1. wood rot
  2. burning paper
  3. antibiotic resistance of bacteria
  4. milk that turns sour
  5. Disinfection of a wound with alcohol
  6. Use of fruit salt to combat heartburn
  7. Burning a candle
  8. Blood clotting
  9. Muscle fatigue after intense exercise
  10. Killing of insects by insecticides
  11. Obtaining Roquefort cheese
  12. obtaining cider
  13. obtaining yogurt
  14. composting
  15. Ensilage
  16. Obtaining bioethanol from molasses
  17. Bloated cans of preserves
  18. Rotten egg
  19. Rusting of a fence
  20. Obtaining biodiesel from palm oil

Chemical phenomena in industry

Certain chemical phenomena are also key in the industry. To begin with, the combustion of hydrocarbons (such as gasoline, diesel or kerosene) produces energy to run the machinery that handles countless industrial processes.

On the other hand, the steel industry, paper, plastics, construction materials, paints, drugs, agricultural products, etc., are based on various chemical phenomena such as galvanization, electrolysis and many others.

The generation of new energy sources (such as biodiesel and bioethanol) is also based on this type of phenomenon.

The transformation of energy

In chemical phenomena it is common for there to be energy transformation. For example, when the chemical energy contained in the bonds of a certain molecule is transformed into electrical energy or released as heat (this occurs in exothermic phenomena, such as when hydrochloric acid is mixed with zinc), there is an energy transformation. The same thing happens when light energy is captured and transformed into chemical energy.

Some chemical processes need heat to be carried out and are called “endothermic”. Others require the presence of catalysts or cofactors.