Table of Contents
Why is heat a path function and enthalpy a state function?
A state function is independent of pathways taken to get to a specific value, such as energy, temperature, enthalpy, and entropy. Enthalpy is the amount of heat released or absorbed at a constant pressure. Heat is not a state function because it is only to transfer energy in or out of a system; it depends on pathways.
Why enthalpy is a state function?
Enthalpy is a state function because it is defined in terms of state functions. U, P, and V are all state functions. Their values depend only on the state of the system and not on the paths taken to reach their values. Therefore, H is a state function.
Why enthalpy change is a path function?
As a state function, enthalpy depends only on the final configuration of internal energy, pressure, and volume, not on the path taken to achieve it. The value does not depend on the path from initial to final state because enthalpy is a state function.
What are state functions and path functions?
A state function is a property describes a particular state, without depending on the path taken to reach this state. In contrast, functions whose value depends on the path taken to get between two states are called path functions.
How are internal energy and enthalpy state functions?
Both enthalpy and the internal energy are often described as state functions. It means that when a system undergoes any change whatever, then the alteration in its enthalpy (or its internal energy) depends only on the initial state of the system and its final state.
Is enthalpy a state variable or state function?
As represented by the solution to the integral, enthalpy is a state function because it only depends on the initial and final conditions, and not on the path taken to establish these conditions.
Why is change in state function not a state function?
State functions are specific for a state. For a given state they will have a definite value which is a characteristic of that state. Enthalpy change is defined for two different states, so it is not a state function.
Is enthalpy path dependent?
Enthalpy is a state function because it depends only on two thermodynamic properties of the state the substance is at the moment (like temperature and pressure, or temperature and entropy, or any pair of other state functions). It does not depend on the path followed by the substance to get there.
Why is enthalpy considered a state function?
Enthalpy is considered a state function because its current value will only depend upon the final and initial values of heat in a reaction, but not the path or process that occurred for it to reach that value.
What is the path function of heat?
Heat, the thermodynamic quantity and the change associated with it is a path function. i.e. it depends on how the system changes from 1 state to another.
Is enthalpy path dependent or state dependent?
Enthalpy is a state function because it is defined in terms of state functions. U, P, and V are all state functions. Their values depend only on the state of the system and not on the paths taken to reach their values. A linear combination of state functions is also a state function. Subsequently, question is, is enthalpy path dependent?
Why is heat not a state function?
Heat is not a state function because it is not an intrinsic property of a system. Think about all the properties which are state functions – pressure, volume, internal energy, temperature, entropy etc.