What are the states of aggregation of water?
Water can be found in nature in three different states of aggregation: solid, liquid and gaseous.
Evaporation: the transition from liquid to gaseous state; Condensation: the passage from the gaseous to the liquid state; Freezing: the transition from liquid to solid state; Sublimation: the transition from the solid to the gaseous state.
aggregation, states of In physics, a way of associating and interacting of the molecules constituting a body or a substance, which determines part of the macroscopic properties of the body itself.
Water does not have a stable shape because, when it flows, the molecules slide over each other. In the gaseous or gaseous state: by increasing the temperature to 100 ° C, the water is transformed into water vapor. This phenomenon occurs when the molecules heat up and start moving, retaining a lot of energy.
In order for a change of state to take place, whatever it may be, it is necessary that the body be supplied or subtracted from heat, otherwise nothing happens. The key feature, however, is that, despite the heat exchange, the body temperature remains constant throughout the entire process.
There are six changes of state (or changes of state) that can occur in matter: ... the transition from solid to liquid state → fusion. transition from liquid to gaseous state → vaporization. transition from gaseous to liquid state → condensation.
Liquid matter has its own volume but does not have its own shape. Liquids always take the shape of the containers that contain them. ... Just like with solids, keeping the volume unchanged, liquids are incompressible at not particularly high pressures.
In the liquid state, the particles, although free to move, are subject to forces of mutual electrostatic attraction and, often, also to intermolecular interactions (bonds between molecules) that are quite strong and tend to arrange themselves in overlapping layers, adapting to the shape of the container that contains them. .
At 0 ° C, i.e. at the point of solidification (or freezing) of the water, a crystal lattice is formed in which each water molecule binds by means of permanent hydrogen bonds with four other water molecules.
Let's imagine we have a glass of water; we put the glass in the freezer and after some time the liquid contained inside will turn into ice. ... Our liquid will then release its heat to the environment until it reaches thermal equilibrium with it.
As temperature and pressure vary, every type of matter, that is, every substance, can pass from one state of aggregation to another, that is, undergo a change of state. A change of state is always accompanied by an exchange of heat between the substance concerned and the surrounding environment.
2.2 States of aggregation of matter
The matter that surrounds us presents itself according to three different "ways of being", which are defined states of aggregation: solid (like rocks), liquid (like water) and gaseous (like air). Solid state materials have their own shape and volume.
molecule, dim. of lat. moles "mole"]. - Chemical combination of two or more atoms, equal to each other (in the elements) or different (in the compounds), which can exist in the free state, and which represents the smallest quantity of matter that possesses the characteristic properties of the substance in question.
A physical process is endothermic if the heat is absorbed by the system at the expense of the environment while if the process is exothermic, energy is released from the system which is gained from the environment. Examples of physical processes are the changes of state to which a change in enthalpy is related.
The materials in the gaseous state (gases and vapors) are easily compressible, and have an indefinite shape and volume so they completely fill the space of a container in which they are contained (for example, water vapor, and the gases present in the atmosphere, such as oxygen and nitrogen).
The pressure exerted by the air affects the boiling temperature of all substances, including water: in the mountains, as we have already said, water boils at a temperature below 100 ° C. Conversely, if the pressure increases, the boiling temperature of the substances also increases.
The solidification point of pure water at a pressure of 1 atmosphere is equal to 0 ° C, but this temperature is generally slightly lower due to the salts naturally dissolved in the water (we speak in this regard of cryoscopic lowering).
When a certain amount of water solidifies, the volume of the ice that forms is considerably greater: consequently the density of the ice (0,917 kg / dm3) is lower than that of water and for this reason the ice floats on the water. .
Condensation (which is the inverse of evaporation) is the transition from the gaseous state (vapor) to the liquid state; when the water contained in a pot boils, we will notice on the window glass and on the kitchen tiles near the pot the formation of tiny droplets of water (condensation) due to the ...
The molecules of a liquid are in continuous reciprocal movement, and, unlike what happens in a gas, they slide over each other without separating. It is for this reason that liquids have their own volume, take the shape of the container that contains them and are practically incompressible.
The forces of attraction that are established inside a liquid and that determine the surface tension are called cohesion forces. ... Vapor pressure Evaporation is defined as the transition to the vapor state of the molecules (or atoms) that make up a liquid.
The physical state of matter is determined by the degree of molecular aggregation. The chemically identical molecules that form the matter manifest a specific mutual attraction called the cohesive force. Note. The degree of attraction between different molecules, on the other hand, is called the adhesion force.
Matter, if subjected to changes in temperature and pressure, undergoes a transformation from one physical state to another, called a change of state, a physical and non-chemical transformation, because the composition of the substance is not altered, but only the way in which the particles are bound.
In correspondence with this the solid body undergoes a change of state, passing from solid to liquid. The temperature at which it occurs is called the melting temperature, if the body is always in the same conditions (constant pressure) the melting temperature is always the same.
Although it continues to heat, throughout the change of state, the temperature remains constant: the energy supplied is used to dilate and melt the substance. ... · A liquid can evaporate at any temperature, but it begins to boil when the maximum vapor pressure equals the external pressure.