Model I:  H+ - SO42− - NO3 - Cl - Br - H2O

Comprehensive Calculation

Here, the model determines the equilibrium state of a system containing water, and two or more ions. Water content is specified either in terms of amount, or as a fixed relative humidity. The formation of solids, and the partitioning of water and individual trace gases between the condensed and vapour phases, can be calculated at the choice of the user. Specify the problem in the input fields below.

Ambient Conditions

(1) Temperature (180 - 330 K):

(2) The water content of the system must be specified as either a (fixed) ambient relative humidity or the number of moles of water present per m3 of atmosphere. Select one:

   Fixed relative humidity        Constant total water

Now enter the relative humidity (range 0.1 - 1.0) or moles of water present:

(3) If the temperature is less than 273.15 K, and you wish the system to be equilibrated to the water vapour pressure over ice, then check the box here. (If constant total water has been selected then this option has no effect.)

Ionic Composition in Moles per m3

H+:     SO42:
NO3:     Cl:     Br:

Other Chemical Components

The amounts of organic compounds present can be entered here. First, click the button to select compounds from the library or create new ones for this session.

Trace Gases

Check the boxes below to disable the partitioning of selected trace gases into the vapour phase. (The default for each gas is that partitioning is calculated.)

Prevent partitioning of the following gases:


Solid Phases

Check the boxes below to prevent the formation of selected solids, as many as desired. This enables the properties of metastable, supersaturated, aqueous aerosols to be investigated. (The default for each calculation is that all solids can form.)

Omit the following solids:

Ice H2SO4 · H2O H2SO4 · 2H2O
H2SO4 · 3H2O H2SO4 · 4H2O H2SO4 · 6.5H2O
HNO3 · H2O HNO3 · 2H2O HNO3 · 3H2O
HCl · 3H2O

To submit your calculation, click here: