.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "api/gallery/electrochem/standard_potentials/plot_01_daniell_cell.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download_api_gallery_electrochem_standard_potentials_plot_01_daniell_cell.py>`
        to download the full example code.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_api_gallery_electrochem_standard_potentials_plot_01_daniell_cell.py:


The Daniell cell: a steady 1.10 V from zinc and copper
========================================================

Daniell's 1836 two-fluid cell separated a zinc electrode in zinc (or acid)
solution from a copper electrode in copper sulfate. Copper metal, not
hydrogen gas, is deposited at the cathode, so the cell does not polarize.
This example reproduces its standard potential with
:func:`~chemistrykit.electrochem.systems.standard_potentials.standard_cell_potential`,
balances the overall reaction with
:func:`~chemistrykit.electrochem.systems.standard_potentials.balance_redox_reaction`,
and uses the Nernst equation to show how gently the voltage falls as the
cell discharges -- the steadiness that made it the first practical voltage
standard.

.. GENERATED FROM PYTHON SOURCE LINES 18-25

.. code-block:: Python

    import matplotlib.pyplot as plt
    import numpy as np

    from chemistrykit.electrochem.systems.nernst import nernst_potential
    from chemistrykit.electrochem.systems.standard_potentials import STANDARD_REDUCTION_POTENTIALS as T
    from chemistrykit.electrochem.systems.standard_potentials import balance_redox_reaction, standard_cell_potential








.. GENERATED FROM PYTHON SOURCE LINES 26-27

Zn(s) + Cu2+(aq) -> Zn2+(aq) + Cu(s)

.. GENERATED FROM PYTHON SOURCE LINES 27-31

.. code-block:: Python

    E0 = standard_cell_potential("Cu2+/Cu", "Zn2+/Zn")
    cathode_mult, anode_mult, n = balance_redox_reaction(T["Cu2+/Cu"], T["Zn2+/Zn"])
    print(f"Daniell cell E0 = {E0:.2f} V; balancing multiples = ({cathode_mult}, {anode_mult}), n = {n}")





.. rst-class:: sphx-glr-script-out

 .. code-block:: none

    Daniell cell E0 = 1.10 V; balancing multiples = (1, 1), n = 2




.. GENERATED FROM PYTHON SOURCE LINES 32-34

As the cell discharges, Cu2+ is consumed and Zn2+ produced
(starting from 1 M each). Q = [Zn2+]/[Cu2+].

.. GENERATED FROM PYTHON SOURCE LINES 34-48

.. code-block:: Python

    extent = np.linspace(0.0, 0.99, 200)
    Q = (1.0 + extent) / (1.0 - extent)
    E = nernst_potential(E0, n, Q)

    fig, ax = plt.subplots()
    ax.plot(extent * 100, E)
    ax.axhline(E0, color="gray", linestyle="--", label=r"$E^\circ$ = 1.10 V")
    ax.set_xlabel(r"Cu$^{2+}$ consumed (%)")
    ax.set_ylabel("Cell voltage (V)")
    ax.set_ylim(0.9, 1.2)
    ax.set_title("Daniell cell voltage during discharge")
    ax.legend()
    fig.tight_layout()
    plt.show()



.. image-sg:: /api/gallery/electrochem/standard_potentials/images/sphx_glr_plot_01_daniell_cell_001.png
   :alt: Daniell cell voltage during discharge
   :srcset: /api/gallery/electrochem/standard_potentials/images/sphx_glr_plot_01_daniell_cell_001.png
   :class: sphx-glr-single-img






.. rst-class:: sphx-glr-timing

   **Total running time of the script:** (0 minutes 0.034 seconds)


.. _sphx_glr_download_api_gallery_electrochem_standard_potentials_plot_01_daniell_cell.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: plot_01_daniell_cell.ipynb <plot_01_daniell_cell.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: plot_01_daniell_cell.py <plot_01_daniell_cell.py>`

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: plot_01_daniell_cell.zip <plot_01_daniell_cell.zip>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_