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

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

Step-by-step 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`