Measure the electrode protential of the given species by connecting the redox couple of the given species with standard hydrogen electrode. If it is positive, the electrode of the given species ascts as reductant and if it is negative, it acts as an oxidant.
Find the electrode potential of the other given species in the same way, compare the values and determine their camparative strength as an reductant or oxidant.
e.g,. measurement of standard electrode potential of `Zn^(2+)//Zn` electrode using SHE as a referernce electrode
The EMF of the cell comes out to be 0.76 V. (reading of voltmeter is 0.76V). `Zn^(2+)//Zn` couple acts as anode and SHE acts as cathode.
`E_("cell")^(@)=0.76=E_("cathode")^(@)-E_("anode")^(@)`
`0.76=0-E_("anode")^(@)`
`E_("anode")^(@)=-0.76V`
`E_(Zn^(2+)//Zn)^(@)=-0..76V`
