science physics

# Why is temperature a state function?

Last Updated: 31st March, 2020

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Temperature is a state function as it is one of the values used to define the state of an object. Furthermore, temperature is dependent on the final and initial values, not on the path taken to establish the values.

Herein, why is temperature not a state function?

Temperature is a state function. Heat and work are not state functions. Work can't be a state function because it is proportional to the distance an object is moved, which depends on the path used to go from the initial to the final state. If work isn't a state function, then heat can't be a state function either.

One may also ask, why Energy is a state function? State functions do not depend on the path by which the system arrived at its present state. For example, internal energy, enthalpy, and entropy are state quantities because they describe quantitatively an equilibrium state of a thermodynamic system, irrespective of how the system arrived in that state.

Secondly, why heat is a path function?

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. Since the way in which heat is transferred depends not on the path taken, isothermal or isobaric etc., the very concept of the path or point function is absurd.

Why internal energy is a function of temperature only?

Pressure and volume change while the temperature remains constant. Since no work or heat are exchanged with the surrounding, the internal energy will not change during this process. Thus, the internal energy of an ideal gas is only a function of its temperature.

Professional

## What do you mean by state function?

A state function is a property whose value does not depend on the path taken to reach that specific value. In contrast, functions that depend on the path from two values are call path functions. Both path and state functions are often encountered in thermodynamics.

Professional

## How do you define enthalpy?

Enthalpy is a thermodynamic property of a system. It is the sum of the internal energy added to the product of the pressure and volume of the system. It reflects the capacity to do non-mechanical work and the capacity to release heat. Enthalpy is denoted as H; specific enthalpy denoted as h.

Professional

## What is meant by the statement internal energy is a function of state?

Internal energy does not depend on the path of the process it has a particular value at each every different states of the system or state points. It is also called as point function.

Explainer

## Why is Q not a state function?

So, in general, our system processes do not happen under such special conditions as perfect constant volume or perfect constant pressure, so in general, q is not a state function because the energy transferred depends on the path chosen.

Explainer

## Is Heat a path function?

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. The concept of path and point functions only appear in thermodynamics which tells you how much quantity of energy is transfered either as heat or work.

Explainer

## Is QP a state function?

qp. Work is a state property as it is directly proportional to the object's distance moved against the opposing force and this distance depends on the path taken. Since deltaU = W + q, and work is a state function, it seems that the heat given off must be dependent on the path as well.

Pundit

## What is Delta H?

In chemistry, the letter "H" represents the enthalpy of a system. Enthalpy refers to the sum of the internal energy of a system plus the product of the system's pressure and volume. The delta symbol is used to represent change. Therefore, delta H represents the change in enthalpy of a system in a reaction.

Pundit

## Is kinetic energy a path function?

Path functions are properties or quantities whose values depend on the transition of a system from the initial state to the final state. so the kinetic energy can not be termed as path function. and as state evolves with time the average value of K.E. can also be defined.

Pundit

## What are the limitations of first law of thermodynamics?

The limitation of the first law of thermodynamics is that it does not say anything about the direction of flow of heat. It does not say anything whether the process is a spontaneous process or not. The reverse process is not possible. In actual practice, the heat doesn't convert completely into work.

Pundit

## What is meant by point function?

A Point function (also known as state function) is a function whose value depends on the final and initial states of the thermodynamic process, irrespective of the path followed by the process. A point function is a property of the system or we can say all the properties of the system are point functions.

Pundit

## What is the difference between heat and temperature?

Often we think that heat and temperature are the same thing. However, this is not the case. Heat and temperature are related to each other, but are different concepts. Heat is the total energy of molecular motion in a substance while temperature is a measure of the average energy of molecular motion in a substance.

Teacher

## Does work depend on Path?

A direct consequence of the closed path test is that the work done by a conservative force on a particle moving between any two points does not depend on the path taken by the particle. The work done by a conservative force is equal to the negative of change in potential energy during that process.

Teacher

## What is the law of entropy tell us?

Entropy is one of the consequences of the second law of thermodynamics. The most popular concept related to entropy is the idea of disorder. Entropy is the measure of disorder: the higher the disorder, the higher the entropy of the system. This means that the entropy of the universe is constantly increasing.

Teacher

## Is heat a property?

Heat is defined as the transfer of thermal energy! Temperature would be an intensive property because it doesn't depend on the amount of substance (a 100 degrees cup of coffee has same temp as a 100 degree drop of coffee), but thermal energy is an extensive property because it does depend on the amount of substance.

Teacher

## What are the properties of a system?

Properties can be intensive, if they are point properties (properties that make sense for a point) or extensive, if they depend on the amount of matter in the system. Examples of extensive properties of systems are mass of system, number of moles of a substance in a system, and overall or total volume of a system.

Reviewer

## What is point and path function?

Path function and Point function are introduced to identify the variables of thermodynamics. Path function: Their magnitudes depend on the path followed during a process as well as the end states. Point Function: They depend on the state only, and not on how a system reaches that state.

Reviewer

## Is work a thermodynamic variable?

Formal definition
Consequently, thermodynamic work is defined in terms of quantities that describe the states of materials, which appear as the usual thermodynamic state variables, such as volume, pressure, temperature, chemical composition, and electric polarization.

Reviewer

## What are examples of a state function?

Mass, pressure, density, energy, temperature, volume, enthalpy, entropy, Gibbs free energy and chemical composition are all examples of state functions in thermochemistry.

Reviewer

## Is enthalpy change a state function?

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). As a result, an enthalpy change is NOT a state function.

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31st March, 2020

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