Given that: E∘Fe2+/Fe=−0.44 V and E∘Fe3+/Fe2+=0.77 V E∘Fe3+/Fe is:
Given standard E⊖:
Fe3++3e−→Fe; E⊖=−0.036V
Fe2++2e−→Fe; E⊖=−0.440V
The E⊖ of Fe3++e−→Fe2+ is: