- #1
HWGXX7
- 46
- 0
Hello,
I'am new here and having some troubles with understanding the difference between 2 related subjects.
I learned that internal energy contains 2 main components: kinetic energy and potential energy.
[tex]U=E_{K}+E_{p}[/tex]
The related first law of thermodynamics (for closed systems): [tex]dU=dQ+dW[/tex]
wich means practically: within the systems heat can be exchanged for work and vice versa. Suppose an ideal system with no loss. Ok so far no problems.
But now the definition of ethalpy (closed system) as I learned it: [tex]H=U+p.V[/tex]
I don't understand why the component [tex]p.V[/tex] is added.
This component is already a component to the internal energy under the form of [tex]dW[/tex]
Do I miss something important in my derivation?
grtz
I'am new here and having some troubles with understanding the difference between 2 related subjects.
I learned that internal energy contains 2 main components: kinetic energy and potential energy.
[tex]U=E_{K}+E_{p}[/tex]
The related first law of thermodynamics (for closed systems): [tex]dU=dQ+dW[/tex]
wich means practically: within the systems heat can be exchanged for work and vice versa. Suppose an ideal system with no loss. Ok so far no problems.
But now the definition of ethalpy (closed system) as I learned it: [tex]H=U+p.V[/tex]
I don't understand why the component [tex]p.V[/tex] is added.
This component is already a component to the internal energy under the form of [tex]dW[/tex]
Do I miss something important in my derivation?
grtz