Creating a `Solution`¶

The Solution class defines a pythonic interface for creating, modifying, and estimating properties of electrolyte solutions. It is the core feature of pyEQL and the primary user-facing class. There are several ways to create a Solution.

Empty solution¶

With no input arguments, you get an empty Solution at pH 7 and 1 atm pressure.

>>> from pyEQL import Solution
>>> s = Solution()
>>> print(s)
Volume: 1.000 l
Pressure: 1.000 atm
Temperature: 298.150 K
Components: ['H2O(aq)', 'H[+1]', 'OH[-1]']

Manual Creation¶

Typically, you will create a solution by specifying a list of solutes. Solutes are passed as a dict with amounts given as strings that include units (see units). Any unit that can be understood by get_amount is valid.

>>> from pyEQL import Solution
>>> s = Solution({"Na+": "0.5 mol/L", "Cl-": "0.5 mol/L"})

You can also specify conditions such as temperature, pressure, pH, and pE (redox potential).

Finally, you can manually create a solution with any list of solutes, temperature, pressure, etc. that you need:

>>> from pyEQL import Solution
>>> s1 = Solution(solutes={'Na+':'0.5 mol/kg', 'Cl-': '0.5 mol/kg'},
                  pH=8,
                  temperature = '20 degC',
                  volume='8 L',
                  pE = 4,
                  )

Using a preset¶

Alternatively, you can use the Solution.from_preset() classmethod to easily create common solutions like seawater:

>>> from pyEQL import Solution
>>> s2 = Solution.from_preset('seawater')
<pyEQL.solution.Solution object at 0x7f057de6b0a0>

From a dictionary¶

If you have converted a Solution to a dict, you can re-instantiate it using the Solution.from_dict() class method.

From a file¶

If you save a Solution to a .json file, you can recreate it using monty.serialization.loadfn

>>> from monty.serialization import loadfn
>>> s = loadfn('test.json')
print(s)
Volume: 1.000 l
Pressure: 1.000 atm
Temperature: 298.150 K
Components: ['H2O(aq)', 'H[+1]', 'OH[-1]']

Creating a Solution¶