Arithmetic Operations

Addition and Subtraction

You can use the + operator to mix (combine) two solutions. The moles of each component in the two solutions will be added together, and the volume of the mixed solution will be approximately equal to the sum of the two volumes, depending on the electrolyte modeling engine used. The pressure and temperature of the mixed solution are computed as volume-weighted averages.

>>> from pyEQL import Solution
>>> s1 = Solution({"Na+": "0.5 mol/L", "Cl-": "0.5 mol/L"})
>>> s2 = Solution({"Na+": "0.1 mol/L", "Cl-": "0.1 mol/L"})
>>> s1+s2
<pyEQL.solution.Solution object at 0x7f171aee3af0>
>>> (s1+s2).get_amount('Na+', 'mol')
<Quantity(0.6, 'mole')>
>>> (s1+s2).volume
<Quantity(1.99989659, 'liter')>


Both Solution involved in an addition operation must use the same electrolyte modeling engine.

Subtraction is not implemented and will raise a NotImplementedError.

>>> s1-s2
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/ryan/mambaforge/envs/pbx/code/pyEQL/src/pyEQL/", line 2481, in __sub__
    raise NotImplementedError("Subtraction of solutions is not implemented.")
NotImplementedError: Subtraction of solutions is not implemented.

Multiplication and Division

The * and / operators scale the volume and all component amounts by a factor.

from pyEQL import Solution
>>> s = Solution({"Na+": "0.2 mol/L", "Cl-": "0.2 mol/L"})
>>> s.volume
<Quantity(1, 'liter')>
>>> s.get_amount('Cl-', 'mol')
<Quantity(0.2, 'mole')>
>>> s*=1.5
<Quantity(1.5, 'liter')>
s.get_amount('Cl-', 'mol')
<Quantity(0.3, 'mole')>

The modulo operator // is not implemented.