# Homework Help: Compressing water vapour

1. Feb 11, 2012

### aaaa202

Okay my exercise says the following:

"By applying a pressure of 200 atm, you can compress water to 99% of its usual volume. Find the work needed to do this."

Now I'm having a bit of trouble with how this is put. For me it doesn't make sense to just put 200atm pressure on normal pressured water vapour. Don't they mean between the lines, that the water has been slowly pressured quasistatically from normal pressure to 200atm pressure?

2. Feb 11, 2012

### wukunlin

we need to know whether this is done isothermally or adiabatically

3. Feb 11, 2012

### aaaa202

The exact text is: "By applying a pressure of 200atm you can compress water to 99% of its usual volume. Sketch this proces (not neccesarily to scale) on a PV diagram, and estimate the work required to compress a liter of water by this amount. Does the result surprise you?"

Now I just want to know if you are to assume that the water is compressed slowly beggining from atmospheric pressure until 200 atm? It doesn't really make sense to just apply 200atm, or am I reading it wrong? Now you are also right that information lacks about it being adiabatic or isothermal..