[bongodongobob]

I never knew this either. This makes sense as when you tap on a propane tank they always sound empty, different than a metal tank of water. Even though it's a liquid and under extreme pressure, it's only the temperature that matters.

[thfuran]

Liquid propane is definitely not an ideal gas.

[bongodongobob]

Not saying it is, but it's very volatile. It really doesn't want to be a liquid at room temperature. I can't tell if it's empty or full when a tap on it, but definitely can with with water. It's an impedance thing.

[thfuran]

I'm just saying a fact about ideal gases doesn't really imply anything about LP.

[bongodongobob]

It does, vapor pressure.

[nautilius]

That's got nothing to do with some fluid behaving like an ideal gas or not. Also, except for very low pressures, vapor does not behave like an ideal gas.

[bongodongobob]

Sure it does, it's riding the border of a phase change between gas and liquid. It's in a super compressed equilibrium so it's going to behave similarly to an ideal gas.

[jldl805]

That's because propane tanks are only 1/4 full even when filled to max capacity.