# Question: Which Is The State Function?

## What is a state change?

A change of state occurs whenever matter changes from one state to another.

Common states of matter on Earth are solid, liquid, and gas.

Changes of state are physical changes in matter.

They are reversible changes that do not change matter’s chemical makeup or chemical properties..

## Is heat capacity a state function?

Heat capacity is an intensive property whereas specific heat capacity and molar heat capacity are extensive properties. However, all heat capacities are state functions since it does not matter HOW the heat was added or HOW the temperature was changed.

## What is not 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. … Thermodynamic properties that are not state functions are often described by lowercase letters (q and w).

## Is mass a state function?

In this lesson, you learned that a state function is a property whose value does not depend on the path taken to reach that specific value. … Mass, pressure, density, energy, temperature, volume, enthalpy, entropy, Gibbs free energy and chemical composition are all examples of state functions in thermochemistry.

## Why Heat is not 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 pressure is a state function?

Pressure is a measure of the average force exerted by the constituent molecules per unit area on the container walls. pressure does not depend on the path of the molecules and thus it is a state function.

## Why temperature is a state function?

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. … As a result, volume is a state function because it is not dependent on the object’s path or history.

## Which quantities are state functions?

The thermodynamic state of a system refers to the temperature, pressure and quantity of substance present. State functions only depend on these parameters and not on how they were reached. Examples of state functions include density, internal energy, enthalpy, entropy.

## What is state quantity?

As already said, the state quantities are the quantities chosen by the scientist or the engineer to describe a phenomenon he wants to predict. The state quantities define the equilibrium: when the state quantities remain constant with respect to the time, the phenomenon is at an equilibrium.

## How do you determine a state function?

trivially: if a quantity is uniquely determined by the equilibrium state then it is a state function, otherwise it is not. ΔU is clearly not a state function, since by its very definition (ΔU=Ufinal−Uinitial) it is not determined uniquely by the state of the system: neither by the final, nor by the initial one.

## What is state function and state variable?

So can we say in other words that: “state variable” is something that we take as independent variable, while “state function” is something that depends on previously selected “state variables” where this dependence is given in the equation of state for the particular thermodynamic system.

## Is heat a state variable?

In thermodynamics, a state variable is an independent variable of a state function like internal energy, enthalpy, and entropy. Examples include temperature, pressure, and volume. Heat and work are not state functions, but process functions.