Enthalpy in physical state changes

Enthalpy is the amount of energy in a given reaction, we can calculate the heat of a system through the change in enthalpy (∆H).
The ∆H in physical state changes:

The figure represents a change in physical state from solid to liquid (melting). It occurs when water goes through an enthalpy of fusion: melting ice resulting from an absorption of heat. The amount of heat needed for this process to occur is 7.3 KJ/mol (fusion of 1 mol of H2You)). Process equation:
H2O(s) → H2the (1) ∆H = + 7.3 KJ/mol

Do not stop now... There's more after the advertising ;)

Now pay attention to the image below:

Notice the steam coming out of the kettle, it demonstrates a change in physical state. The water inside the kettle was in a liquid state, but due to the absorption of heat it changed to a gaseous state. The heat required for the enthalpy of vaporization to occur in 1 mol of H2O(1) is 44 KJ/mol, according to the equation:
H2O (1) → H2the (v) ∆H = + 44 KJ/mol
By Líria Alves
Graduated in Chemistry
Brazil School Team

Physicochemical - Chemistry - Brazil School

Would you like to reference this text in a school or academic work? Look:

SOUZA, Líria Alves de. "Enthalpy of changes in physical state"; Brazil School. Available in: https://brasilescola.uol.com.br/quimica/entalpia-nas-mudancas-estado-fisico.htm. Accessed on June 28, 2021.

Molarity or Molar Concentration

Molarity (M) is the relationship between the solute matter (n) and the volume of a solution (V), ...

read more

Molality or Molal Concentration

Molality (W) is one of the ways to measure the concentration of solute in solvent, that is, the n...

read more

Electrochemistry: summary, batteries, electrolysis and exercises

Electrochemistry is the area of ​​Chemistry that studies the reactions that involve the transfer ...

read more