Cu2+ (aq) 2e- cu (s: anode: the electrode where oxidation (loss of electrons) takes place, cathode: the electrode where reduction (gain of electrons) takes place. F"13 chem 2880: cell diagrams are used to describe these types of electrochemical cell. H+ (1 m) + e- h2 (1 atm) F"13 chem 2880: all half-cell reactions are reversible, can act as cathode or anode, for reverse reaction, reverse sign of e , thus the standard potential for a cell can be calculated as. E cell = e cathode - e anode: the sign for the anode is reversed because the standard potentials are written as reductions, and the reaction at the anode is an oxidation. Q, we have: maximum work = nfe = gr. Example: calculate the standard cell potential, g and k for the following cell at. Pt(s)| br2(l)| br (aq) | | h+ (aq)| o2(g) |pt(s) E versus t will have a slope of s .
Here, Zn undergoes oxidation by losing 2eâ, and the Cu2+ ions accept 2eâ to form metallic Cu, which is deposited at the copper electrode. At the zinc electrode, oxidation occurs, and hence it is known as the anode. Reduction occurs at the copper electrode, and hence it is called the cathode.
The electrochemical cell notation for this cell is Zn(s)|Zn2+(aq)||Cu2+(aq)|Cu(s).
Construction of a voltaic cell
Consider a chromium-silver voltaic cell that is constructed such that one half-cell consists of the chromium, Cr, electrode immersed in a Cr(NO3)3 solution, and the other half-cell consists of the silver, Ag, electrode immersed in a AgNO3 solution. The two electrodes are connected by a copper wire. The Cr electrode acts as the anode, and the Ag electrode acts as the cathode. To maintain electric neutrality, you add a KNO3 salt bridge separating the two half-cells. Use this information to solve Parts B, C, and D.
Part B
The half-cell is a chamber in the voltaic cell where one half-cell is the site of the oxidation reaction and the other half-cell is the site of the reduction reaction.
Type the half-cell reaction that takes place at the anode for the chromium-silver voltaic cell. Indicate the physical states using the abbreviation (s), (l), or (g) for solid, liquid, or gas, respectively. Use (aq) for an aqueous solution. Do not forget to add electrons in your reaction.
Express your answer as a chemical equation.
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Part C
The half-cell is a chamber in the voltaic cell where one half-cell is the site of an oxidation reaction and the other half-cell is the site of a reduction reaction.
Type the half-cell reaction that takes place at the cathode for the chromium-silver voltaic cell. Indicate physical states using the abbreviation (s), (l), or (g) for solid, liquid, or gas, respectively. Use (aq) for an aqueous solution. Do not forget to add electrons in your reaction.
