# Joule-Thompson experiment

1. Sep 13, 2007

### zeshkani

1. The problem statement, all variables and given/known data

Show that the Joule-Thompson experiment is an isenthalpic process. (ΔH=0). The experimentally determined quantity is (Partial derivative T)/(Partial derivative P)H . Starting with the total differential for H, show that:

(Partial deriv H)/(Partial deriv P)T = - Cp(Partial deriv T)/(Partial deriv P)H

does anybody know even where to start ??, iam just confused with this question

2. Sep 14, 2007

### Kurdt

Staff Emeritus
Do you know what the total differential of H is?

3. Sep 14, 2007

### zeshkani

no i dont, since i never took calc 3 and still having some hard time partial derivatives

4. Sep 14, 2007

### Kurdt

Staff Emeritus
The total differential of H is:

$$dH=C_p dT+ \left[ v - T \left( \frac{\partial v}{\partial T} \right) _p \right] dp$$

Last edited: Sep 14, 2007
5. Sep 14, 2007

### zeshkani

those this even seem right ??

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6. Sep 16, 2007

### Kurdt

Staff Emeritus
If its isoenthalpic the dH is going to be zero. You're almost there.