Introduction
In
Lesson 5, we examined solid/aqueous phase equilibrium in
solutions containing two salts. Here we study
the gas phase partitioning in a system containing the ions Na
+,
NH
4+, H
+, and
NO
3−.
Preparation
Before starting, ensure that this browser window occupies only the
left half of your screen. You should leave enough
space for another browser window where you can
enter data into
E-AIM and read the results. If your screen is too small for
two windows, print out this tutorial and use this window to run the
E-AIM model. In these lessons we assume that you will
have two browser windows open.
Select this
link to open a second browser window containing the data
input page for "comprehensive" calculations using Model III
(http://www.aim.env.uea.ac.uk/aim/model3/model3b.php). Arrange
the windows on your screen so that both are visible and the left window
contains this text.
The Lesson
This consists of the three sets of calculations described in the links below,
which should be done in the order listed.
You have completed Lesson 6, and learned that:
- Non-volatile compounds such as sodium nitrate force the existence of a
particulate phase under all conditions. This may be liquid or solid according to the relative
humidity.
- The particle phase may be solid or aqueous or a mixture
of the two depending on the chemical composition of the system,
and whether volatile compounds (here HNO3 and
NH3) are allowed to partition into the gas phase.
- Where there is equilibration between gas, liquid, and solid phases
the behaviour of the system can be complex even at a fixed relative humidity.
In part (c) of the lesson the equilibrium particulate phase ranged through
solid, solid + liquid, liquid only, and to no particulate phase just by
substituting the cation NH4+
for Na+.
Now proceed to Lesson 7, which examines how
the properties of single electrolyte solutions depend upon temperature.