- #1
member 392791
I am having confusion with the difference between these two, or are they synonymous terms?
They are synonymous terns.Woopydalan said:I am having confusion with the difference between these two, or are they synonymous terms?
morrobay said:Enthalpy of vaporization is the heat , calories/gram, absorbed during phase change from liquid to gas.
For example the heat water at 100 C absorbs going to steam at 100 C
Latent heat of vaporization , usually called latent heat of fusion, is that quantity
of heat released during condensation. The phase change back to a liquid at 100 C from gas at 100 C.
Chestermiller said:The term "fusion" is reserved for the melting of a substance from solid to liquid. That's the definition of the word fusion.
morrobay said:I should have said latent heat of condensation then. The key word here is latent, and from my 1A and 1B chemistry classes
it applies when heat previously absorbed during phase change : solid to liquid and
liquid to gas is released in the reverse.
Understanding the concepts of enthalpy of vaporization and latent heat of vaporization is crucial in thermodynamics and phase transitions. Let's address some common questions about these related but distinct terms:
The enthalpy of vaporization, often denoted as \(\Delta H_{\text{vap}}\) or \(H_{\text{vap}}\), is the amount of heat energy required to convert a given quantity of a substance from a liquid state to a gaseous state at a constant temperature and pressure. It is expressed in joules per mole or calories per gram.
The latent heat of vaporization is synonymous with the enthalpy of vaporization and represents the same concept. It is the heat energy required to change the phase of a substance from a liquid to a gas without a change in temperature at a constant pressure.
The existence of two terms, "enthalpy of vaporization" and "latent heat of vaporization," is primarily due to historical and terminological differences. Enthalpy is a thermodynamic property that includes both internal energy and pressure-volume work, while latent heat focuses solely on the energy associated with phase changes. In practice, the terms are interchangeable.
The enthalpy of vaporization is typically measured experimentally using calorimetry. A sample of the substance is heated at a constant pressure until it changes from a liquid to a gas. The heat energy absorbed during this phase transition is measured and divided by the number of moles to determine the enthalpy of vaporization.
The enthalpy of vaporization is a crucial thermodynamic property used in various scientific and engineering applications. It plays a significant role in processes such as distillation, evaporation, and refrigeration. It also helps understand the energy required for the phase transition of a substance.
Yes, the enthalpy of vaporization varies from one substance to another. Different substances require different amounts of energy to change from a liquid to a gas at the same temperature and pressure. This property is specific to each substance and is often listed in reference tables.
Here are some approximate values for the enthalpy of vaporization for a few common substances:
In summary, the terms "enthalpy of vaporization" and "latent heat of vaporization" represent the same thermodynamic concept—the heat energy required for the phase change from liquid to gas. These terms are interchangeable, and the property is essential in understanding phase transitions and energy transfer during vaporization processes.