20 Examples of Chemical Changes

The chemical changes (or chemical reactions) are modifications that the substances and that turn them into different ones. This is because they undergo a modification in their nature. They are changes that a substance undergoes and that involve breakdown and the formation of chemical links to generate a new substance.

Chemical changes differ from Physical changes since in physicists there is no transformation in nature, but there is simply a change of state, volume or shape.

For example, when you put water in a pot and this boils, goes out of state liquid to gaseous. This process is a reversible physical change, that is to say, that the water vapor can return to being liquid when changing the pressure conditions or temperature.

The chemical changes, then, they are not always reversiblewhile physicists generally are. Furthermore, chemical changes can be analyzed from two points of view:

Types of chemical changes

Chemical changes can be classified depending on the type of substances that react (inorganic or organic). In addition, reactions can be defined according to several criteria, some of which are:

Inorganic reactions

• Reactions that release energy in the form of heat. For example:
  
• Reactions that absorb energy in the form of heat. For example:
  
• Reactions that release energy in the form of light. For example:
  
• Reactions that absorb energy in the form of light. For example:
  
• Quick reactions. For example:
  
• Slow reactions For example:
  
• Reversible reactions. For example:
  
• Irreversible reactions. For example:
  
• Reactions acid-base. For example:
  

Organic reactions

They are classified according to many factors such as the type of compound that reacts, the type of reaction it undergoes, the conditions under which the reaction occurs, and many more. Some organic reactions are:

• Combustion from alkanes. For example:
  
• Halogenation of alkanes. For example:
  
• Hydrogenation of alkenes. For example:
  
• Halogenation of alkenes. For example:
  
• Halogenation of alcohols. For example:
  
• Halogenation of alkynes. For example:
  
• Hydration of alkynes. For example:
  

Examples of chemical changes

Here are some chemical changes:

1. When we burn logs to make a fire, a chemical change occurs. This is because the wood in the logs turns to ash and, in turn, releases some gases, such as carbon dioxide.
2. The production of water, as a consequence of the combination of two molecules of hydrogen and one of oxygen.
3. The transformation of starch into different types of sugar, when they come into contact with saliva, at the moment in which we digest it.
4. When we combine sodium with chlorine and they react, as a consequence common salt is obtained, also called sodium chloride.
5. In the digestion of food, what we eat is then transformed into the energy we need to live and to carry on different activities, from the basic ones such as walking and breathing, to the more complex ones, such as thinking and to work.
6. During photosynthesis (a process carried out by plants), the solar energy it becomes your power source.
7. When atoms are transformed into ions.
8. Diesel, as a result of the refining processes that oil undergoes.
9. When we put a piece of paper in a flame of fire and it burns and turns to ashes.
10. Baking a cake mix (it can no longer be returned to its previous state).
11. The burning of gunpowder, when we light a firework or when we shoot a weapon.
12. When we forget the fruits outside the refrigerator for several days, the bacteria they begin to act on them, until they oxidize them.
13. The transformation of wine into vinegar occurs when bacteria begin to act and transform the ethyl alcohol in what is known as acetic acid.
14. Cooking a piece of pork on a griddle.
15. Ammonia, which is produced from the mixture of nitrogen and hydrogen.
16. When the grape ferments (which implies a change in the sugar contained in the fruits) and turns into wine.
17. When we breathe, we inhale oxygen, which is then converted into carbon dioxide that we exhale.
18. The combustion of gasoline in a motorcycle when it is running.
19. When we prepare a fried egg.
20. The production of bioethanol for use as biofuel.