# Homework Help: Physical Chemistry water vapor/phases present question?

1. Oct 17, 2012

### qnzbabi91

23.7 g of water is in a container of 23.7 L at 298.15 . The vapor pressure of water at this temperature is 23.76 Torr.
A) What phases are present?
B) At what volume would only the gas phase be present?
C) At what volume would only the liquid phase be present?

A) I know that only the gas and liquid are present.

B) I used RT/(nP) to find the volume and got (0.08314*298)/(23.7/18 * 23.76 * 133.322/10^5) = 594 L

C) I used 0.018* 23.7/18.02 = 0.024 L

Thanks for any help! =]

2. Oct 17, 2012

### Staff: Mentor

3. Oct 17, 2012

### qnzbabi91

Okay, so 23.76 is the P in torr so I converted to Pa by multiplying by 133.322 and then I divided by 10^5 to convert Pa to bar. In my textbook the authors used bar so I thought I should as well.

For the second part, I found the 0.018 Vm of gas in my physical chemistry textbook, so I just multiplied it by the number of moles in question.

I am semi-confused.

4. Oct 17, 2012

### Staff: Mentor

$\frac{RT}{nP}$ is an incorrect formula.

And I have no idea what you did in C. However, the only way to have no gas is to have whole volume occupied by liquid.