Editing Half-reaction (section)

==Example: Zn and Cu Galvanic cell==
[[File:Galvanic cell with no cation flow.svg|thumb|right|300px|Galvanic cell]]

Consider the Galvanic cell shown in the adjacent image: it is constructed with a piece of [[zinc]] (Zn) submerged in a solution of [[zinc sulfate]] ({{chem2|ZnSO4}}) and a piece of [[copper]] (Cu) submerged in a solution of [[copper(II) sulfate]] ({{chem2|CuSO4}}). The overall reaction is:

:<chem>Zn_{(s)}{} + CuSO4_{(aq)} -> ZnSO4_{(aq)}{} + Cu_{(s)}</chem>

At the Zn anode, oxidation takes place (the metal loses electrons). This is represented in the following oxidation half reaction (note that the electrons are on the products side):

:<chem>Zn_{(s)} -> Zn^2+ + 2e-</chem>

At the Cu cathode, reduction takes place (electrons are accepted). This is represented in the following reduction half reaction (note that the electrons are on the reactants side):

:<chem>Cu^2+ + 2e- -> Cu_{(s)}</chem>