Using Henry's law to calculate ammonia concentration?

[Hopper295]

TL;DR

How do I calculate the concentration of ammonia in air above a ammina solution of a known concentration

We have a closed chamber of 20 liters. The bottom of this chamber is filled with ammonia solution of 5% (=2,7M/liter). The solution temperature is controlled at 40°C

I would like to calculate the concentration of ammmonia in the chamber air, above the solution. It should be something with henry's law but I don't knwo how to do this...
An approximation would already be super...

Hope someone can help me, thanks!

 

[Dr_Nate]

You'll want to learn about the concept of vapour pressures first.

 

[Hopper295]

Hi dr. nate,

To be honest I don't know much about this...

can you explain some more what you mean?

 

[Dr_Nate]

This is the part where you go try and educate yourself. There are plenty of website out there. Here are two:
https://www.usgs.gov/special-topic/...ce_center_objects=0#qt-science_center_objects
and
https://www.chem.purdue.edu/gchelp/liquids/vpress.html

 

[Hopper295]

Ok thanks. I was already trying to do it myself using googel, but this doesn't go so well.
I was actually hoping someone would find this easy and show me how to do it.

 

[mjc123]

Googling "ammonia solution vapor pressure" gives these, for example:
https://en.wikipedia.org/wiki/Ammonia_(data_page) [see table "Vapor over aqueous ammonia solution"]
https://www.google.co.uk/url?sa=t&r...00i00146.pdf&usg=AOvVaw2la1MUyFpbSH6RRxK4gtxc [Watch out for units!]