I'm trying to find some information on how to find a way to diffuse hexane and HCl, but as they're both in liquid form, I would have to change the system parameters. Is it possible to find their diffusivity constants using pressure readings?

What is your setup.. Conc. hcl hives of hcl fumes which were good for simple diffusion labs. As for hexane it boils at 69 degrees celcius.. asuming you can change temperature you can get gaseous hexane too..

Pardon if the image is too dark - MS Paint doesn't allow bright/contrast editing...

 

Here's what the valves are:

Valve 1: Gate valve for mixing the gases

Valves 2,3: Two ends of mixing chamber

Valve 4: Connects system to vacuum pump

Valves 5,6,7: Connects to chose gas source

Valve 8: Connects gas to system

 

The experiment was initially done as two experiments: Argon and Helium with Carbon Dioxide as a carrier gas. The initial pressures of both components (be it CO2 and Ar or CO2 or He) would be taken, and then the Argon/Helium would mix with the CO2. The system pressure would be recorded and then the cold trap would be immersed in Liquid Nitrogen to freeze the CO2. The Ar/He would be vacuumed out and another pressure reading would be recorded.

 

The diffusion constants for the gas pairs would be calculated using some equations for the text...

 

The question was if it would be possible for hexane and HCl to be put in that setup and measure their diffusivity constants or if not, how ...

 

I've been trying to figure this one out with some friends, and no one seems to know. Unfortunately, I have to seek elsewhere for help

Well, Like i said above.. in order to get HCl as a gas, you need concentrated HCl liquid. In a 38% solution of HCl, the liquid boils at 48 degrees celcius. Of course the gas escapes before that (you will see relatively thick fumes at room temperature). Collect that gas and now you have HCl. As for Hexane.. I would heat it up and collect it as a gas too. That's all I know really. Hope this helps

Much appreciated