Oxidation is a process in which electrons are lost from the substance. Since electrons are lost, oxidation state increases.
In the above reaction, we can see that oxidation state increases for Mn from 0 to +2. That mean Mn is undergoing oxidation.
[tex] Mn(s)----->Mn^{2+}(aq) +2e^{-} [/tex]
We have [tex] E_{ox} = 0.34V [/tex]
The oxidation state decreases for Cu, that means Cu undergoes reduction.
[tex] Cu^{2+}(aq) + 2e^{-} ------> Cu(s) [/tex]
[tex] E_{red} =1.18V [/tex]
The formula to calculate cell potential is
[tex] E_{cell} = E_{ox} + E_{red} [/tex]
Let us plug in the given Eox and Ered values.
[tex] E_{cell} = 0.34V+1.18V [/tex]
[tex] E_{cell} = 1.52V [/tex]
The overall cell potential is +1.52V