Question

How is an oxidation half-reaction written using the reduction potential chart? How is the oxidation potential voltage determined?

Answer 1

Oxidation  half  reaction  is  written   as    follows when  using  using  reduction potential  chart
example  when  using  copper  it is  written  as  follows
CU2+   +2e-  --> c(s)  +0.34v
 oxidasation  is the  loos  of  electron  hence copper oxidation  potential  is  as  follows
cu (s)  -->  CU2+   +2e    -0.34v

Answer 2

Answer:

Oxidation half reaction is the reverse of the reaction depicted in the chart and the oxidation potential will have the opposite sign relative to that in the chart

Explanation:

Redox reactions i.e. reduction-oxidation reactions generally involve transfer of electrons between two species.

Reduction half reaction involves the gain of electrons whereas oxidation half reactions involve the loss of electrons. For example

Oxidation: Loss of electrons

$A\rightarrow A^{+} + e^{-}$

Reduction: Gain of electrons

$A^{+}+e^{-}\rightarrow A$

A reduction potential chart gives the standard reduction potential of various species in terms of the reduction half reaction.

For example, in the case of Zn, the standard reduction potential value (E⁰) would be:

$Zn^{+}+2e^{-}\rightarrow Zn       E0(reduction) =-0.76 V$

The corresponding oxidation reaction and potential would be the reverse of the above reaction:

$Zn\rightarrow Zn^{+}+2e^{-}        E0(oxidation) =+0.76 V$