Matter can be found in different forms or phases, these are known as states of aggregation of matter and are simultaneously exposed to various types of changes that can occur naturally or humanly. We find three different states of aggregation, the liquid , the gaseous and the solid . When these are exposed to certain processes, a change of state occurs , but they do not undergo any type of modification in their composition .
What is the change of state?
The change of state is a type of evolution that a substance undergoes in the states of aggregation but without registering any type of modification in terms of its composition . It is a change that occurs only in the physical characteristics of the elements.
- Definition of state change
- When a state change occurs
- Examples of state change
Definition of state change
In the field of physics and chemistry it is common to hear the word change of state . This refers to the different changes in evolution that matter can undergo in its states of aggregation (physical, liquid or solid) but without any type of change in its chemical composition, in other words, it is a change It is presented in the physical characteristics of a certain element.
When a state change occurs
In general , changes in the state of matter occur when there is a significant increase or decrease in the temperature to which the element is exposed. At this point it is important to understand and know the term latent heat which refers to the heat that is needed to be able to cause a change in the complete state of an element. All the latent heats of substances or elements are a characteristic parameter of each substance and their value will always depend on the pressure.
There are several types of status changes that can occur. Due to the increase in temperature the following may occur:
- Fusion : consists of the step that occurs in a substance that goes from a solid to a liquid state . The temperature that occurs so that the melting can be generated is known as the melting point . In this process, there is a moment in which, after heating a certain solid, it ends up transforming into a liquid . All substances have their melting point determined.
- Vaporization : the term refers to the change that occurs from a liquid to a gaseous state . Vaporization can occur through two different processes, boiling and evaporation . Evaporation occurs on the surface of liquids and boiling is a process that occurs throughout the liquid. The temperature at which this change can occur is known as the boiling point .
- Sublimation : in this change of state, the transition from the solid state to the gaseous state occurs, without having to go through the liquid state during the process.
When the temperature drops significantly, the following types of state changes can occur:
- Solidification : solidification is the passage from a liquid to a solid through cooling . This type of process is considered exothermic and the point at which it can occur is known as the solidification or freezing point.
- Condensation : condensation is a change that occurs in elements when they go from a gaseous to a liquid state . The temperature at which this phenomenon can occur is known as the dew point .
- Reverse sublimation : it is the change of matter that is in the gaseous state when it manages to go to the solid state without having to go through the liquid state first. It is also known by the name of reverse crystallization .
There are many applications in which state changes can be used. Some examples are mentioned below:
- Works in laboratories for different industrial applications through the distillation process, which requires condensation.
- Through fusion and solidification , different types of objects can be made when the materials from which they are made are melted and poured into a given mold.
- The evaporation of the water is used to carry out the extraction of salt in the salt flats.
- To obtain copper through smelting and later to melt it.
- They are used by metallurgical industries to melt metals and make different alloys.
- In welding processes that use a metal at high temperatures that allows them to join other pieces of metal.
- Manufacture of building materials such as bricks and cement blocks.
Changes in the state of matter are important because they make it possible to separate and unite different types of substances . They are also essential to be able to understand and carry out the transport of some fluids , because thanks to the changes in state it is possible to store some compounds or elements and thus facilitate their transport. They are also important for the field of industry and many of these processes turn out to be a fundamental part of living beings and everything that surrounds them.
Some of the changes in the state of matter are even used in daily life, we can observe them for example when we freeze water or when we boil some liquid. They are common and important in practically all daily activities.
Examples of state change
Water state change
Water has the great ability to change from one state to another simply by varying the temperature to which it is exposed. In addition, you can make your state changes by means of different methods, such as:
- Evaporation : when the water goes from the liquid to the gaseous state at the moment in which its temperature rises to 100 ° C.
- Condensation : occurs when water transforms from a gaseous state to a liquid when there is a loss of heat. We can see it when after a shower, the water vapor condenses on the bathroom mirror because the surface of it is colder.
- Freezing : the passage of water from a liquid to a solid state when the temperature drops below 0 ° C.
- Melting : it is a process in which water goes from a solid state to a liquid at the moment in which heat is added to the ice.
- Sublimation : it is a process by which water can go from a gaseous state to a solid. It is what we commonly know as water vapor and for it to occur, the temperature and pressure of the water must be specific.
Change of chocolate status
Chocolate can also undergo various types of changes in the state of matter. For example, when heated to 68 ° C it can reach a crystalline phase allowing the chocolate to become liquid without changing its components. Chocolate can also be cooled to the point of freezing and if enough heat is applied to it, it can melt easily, even after cooling it will return to its solid phase on its own.