Characteristic chemical phenomena and examples

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Anthony Golden

The chemical phenomena They are all those that comprise a series of chemical reactions and that occur in daily life. Although it is true that chemical reactions can be studied or carried out in a laboratory, chemical phenomena can be seen anywhere; outdoors, in the clouds, in our bodies or in the kitchen itself.

Some examples of chemical changes are burning wood, digesting food, cooking an egg, rusting iron, baking a cake, rotting fruit, roasting meat, exploding fireworks, among others..

Cookie baking is one of countless everyday chemical phenomena that everyone knows about. Source: holmespj via Pixabay.

It is easy to recognize chemical phenomena, although they are not isolated but in conjunction with physical (or biological) changes. It is said that a chemical phenomenon has occurred when an increase in temperature, release of gases, sudden illumination, formation of precipitates is observed; or changes in smell, color, or texture.

However, all chemical phenomena share in common the transformation in the identity of matter; the breaking of bonds to establish new ones, the disappearance of reactants to generate products.

A "simple" chemical phenomenon can encompass or pigeonhole a vast number of chemical reactions that obey one or more mechanisms. This occurs particularly when we cook, bake (cookies in the image above) or eat, as well as in interesting biochemical processes such as bioluminescence..

Article index

  • 1 Features
  • 2 Examples
    • 2.1 Crystallization of minerals
    • 2.2 Combustion
    • 2.3 Acid rain
    • 2.4 Ozone production and deterioration
    • 2.5 Fermentation
    • 2.6 Cooking
    • 2.7 Caramelization and Maillard reaction
    • 2.8 Bioluminescence
  • 3 References

Characteristics

Each separate chemical reaction has a set of characteristics that allows them to be recognized or classified from the rest; be these double displacement (metathesis), precipitation, neutralization, addition, isomerization, oxide-reduction, hydrogenation, combustion, pyrolysis, saponification, polymerization and many others..

Some of them can be reversible (the products re-form the reactants) or irreversible (there is only product formation). Also, some are exothermic, endothermic, slow or fast (with or without catalyst).

All however agree on a change in the identity of matter (atom, functional group, molecule, etc.). This causes a variation in one of the properties of the system, which are: color, odor, pH, temperature, pressure, viscosity, mass, volume, density, refractive index, among others..

It is also common to observe bubbling, the appearance of precipitate or double phases, flashes, or explosions. A chemical phenomenon is then characterized by showing a combination of such changes, and can also consist of a series of reactions or transformations closely related to each other..

That is why, depending on the prism with which it is viewed, chemical phenomena refer mainly to all natural or daily processes where it is perceived that there were one or more simultaneous chemical reactions.

Examples

Mineral crystallization

Some minerals crystallize due to the action of water evaporation. Source: Pxhere.

Although not all mineral crystallization mechanisms are strictly chemical phenomena, it is when they proceed from an aqueous solution, which slowly evaporates while the ions group together and form salt crystals..

Water currents can carry ions from rocks to other regions, where they eventually evaporate and leave a trail of crystals; as happens, for example, in salt lakes.

Combustion

Where there is fire there is vigorous and highly exothermic oxidation. When lighting the head of a match, it burns with the oxygen in the air to produce oxides, which is evidenced not only by heat, but also by the color change in the match from red to black..

A fire is, therefore, a chemical phenomenon that involves the formation of many oxides; although if it occurs in a forest, jungle or mountain, these will consist almost entirely of carbon monoxide, as well as oxides of nitrogen and sulfur.

Acid rain

Acid rain is a chemical phenomenon that involves the hydration of various gaseous acid oxides (NOx, SW3, ClOtwo, COtwo). These gaseous oxides when interacting with the water droplets in the clouds are transformed into their respective oxoacids (HNO3, HtwoSW4, HClO3, HtwoCO3), which end up being dumped in the rain.

Acid rains are characterized by their high HNO content3 and HtwoSW4, affecting aquatic ecosystems, crops, acidifying river water and deteriorating marble statues.

Ozone production and deterioration

Ozone in the stratosphere is produced when oxygen reacts with ultraviolet radiation from the sun; and its natural destruction, although by a different mechanism, regenerates oxygen again.

However, there are chemical species that, due to ultraviolet radiation, decompose into free radicals that destroy ozone, inhibiting its protective action..

Fermentation

Fermentation is an example of a chemical phenomenon because microorganisms catalyze reactions on an organic substrate, which is generally a food, juice or drink, to generate a drastic change in its organoleptic properties; especially when it comes to flavor, as with beer and wine.

To cook

Cooking is carrying out a series of chemical phenomena so that a breakfast, lunch or dinner can be made from the ingredients. Source: Milly Eaton via Pexels.

A book could be written that is versed in all the chemical phenomena that take place while we cook. To begin with, the use of fire already implies the denaturation of the proteins that make up food, their dehydration, and the breaking of certain bonds to generate products that intensify their flavors and colors..

Boiling an egg, baking breads or cookies, frying chicken or steaks, making coffee, heating pasta, dressing a salad with vinegar, fermenting pineapples, adding lemon to fish to neutralize their volatile amines, etc., are essentially examples of chemical phenomena.

Caramelization and Maillard reaction

The caramelization reaction of the sugar is used in the preparation of the cheese caramel. Source: Guillermo Amador (flickr.com)

Another particular chemical phenomenon that occurs frequently within the kitchen is caramelization. This consists of partially burning a sugar solution until it turns golden or brown; that is, it stops just when the caramel is ready.

Sugars begin to dehydrate due to the action of heat to produce a compendium of molecules; some small ones (furanone and maltol), thanks to which the caramel has its characteristic smell; other polymeric (caramelina and caramelano), responsible for the caramel colors.

When the sugars are accompanied in addition to proteins, the Maillard reaction occurs, where now the sugars react with the amino groups of these.

Again, it is typical to observe the chemical phenomenon that involves such a reaction in the baking of cookies or cakes, in the preparation of beers, in the frying of bacon, in the browning of meats, in the roast of chicken, in the toasting of the cereals, etc.

Bioluminescence

The illuminated shoreline of a beach at night hours thanks to the bioluminescence of dinoflagellate algae. Source: Jed from San Diego, California Republic [CC BY-SA 2.0 (https://creativecommons.org/licenses/by-sa/2.0)]

Finally, and no less important or curious, we have bioluminescence, where organisms or creatures are capable of generating, through the action of the luciferase enzyme on the luciferin protein, their own light. A clear example is seen in the fireflies and their yellow blinks throughout the night..

References

  1. Whitten, Davis, Peck & Stanley. (2008). Chemistry. (8th ed.). CENGAGE Learning.
  2. Shiver & Atkins. (2008). Inorganic chemistry. (Fourth edition). Mc Graw Hill.
  3. Elsevier. (2019). Chemical Phenomena. Recovered from: sciencedirect.com
  4. Helmenstine, Anne Marie, Ph.D. (October 16, 2019). Examples of Chemical Reactions in Everyday Life. Recovered from: thoughtco.com
  5. Wikipedia. (2019). Chemical reaction. Recovered from: en.wikipedia.org
  6. Rice University. (2019). Classifying Chemical Reactions. Recovered from: openstax.org
  7. The Biomimicry Institute. (January 27, 2017). Chemistry of Nature. Recovered from: asknature.org
  8. Ashley Hamer. (May 14, 2018). 10 Ways to Hack Your Cooking with Chemistry. Recovered from: curiosity.com
  9. Compound Interest. (2018). Food Chemistry - The Maillard Reaction. Recovered from: compoundchem.com
  10. Ashish. (March 25, 2018). Why Does Sugar Turn Brown When Melted? Recovered from: scienceabc.com

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