I in understanding State functions

In summary, a state function is a variable that depends only on the current state of a system, such as temperature, pressure, and amount of a substance. This is different from a scalar quantity, which can be pathway dependent. The equation ΔH=q shows that the final and initial values of H are state functions, while their sum (q) is a scalar quantity. The concept of state functions is important to understand in thermodynamics.
  • #1
crashdirty86
21
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Homework Statement




What is a state function? How is it different from a scalar quantity? Use the expression ΔH=q as an example.

Homework Equations





The Attempt at a Solution



So the way I am interpreting this question is that a state function is a reference to say the temperature, pressure, and amount of a substance, not how the substance is acquired, its present state. A scalar quantity would be an amount of say temperature, making it pathway dependent. Using teh above equation, I believe that the H-final and H-initial are state functions, and their sum is a scalar quantity that is not a state function.

I am really confused on this topic, any help would be much appreciated.
 
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  • #2
It's just testing that you know the definition of a state function.
http://en.wikipedia.org/wiki/Functions_of_state

You seem to have the main point - to be a state function or variable, it's value must only depend on the state, while any old variable could depend on anything.

With reference to the relation provided - what are the variables supposed to represent?
Does the outcome (q) depend on how one gets from H_i to H_f ?
 

1. What is a state function?

A state function is a property of a system that only depends on its current state, and not on how it reached that state. In other words, it is a characteristic of a system that remains constant regardless of any changes in the system's environment or path.

2. How is a state function different from a path function?

A path function is a property of a system that depends on the path or process used to reach a particular state. Unlike state functions, path functions can vary depending on the specific conditions or processes involved in reaching a particular state.

3. What are some examples of state functions?

Some common examples of state functions include temperature, pressure, density, volume, and internal energy. These properties only depend on the current state of the system, and are not affected by the path or processes used to reach that state.

4. How are state functions useful in scientific research?

State functions are useful because they provide a way to simplify complex systems and understand their behavior. By focusing on state functions, scientists can make predictions and draw conclusions about a system without having to consider all the intricate details of its processes.

5. Can state functions change over time?

No, state functions remain constant as long as the system remains in the same state. However, the values of state functions can change when the system undergoes a phase transition or a change in state, but the function itself does not change.

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